[Federal Register: August 25, 2005 (Volume 70, Number 164)]
[Rules and Regulations]
[Page 49977-50073]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25au05-12]
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Part II
Department of Transportation
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Federal Motor Carrier Safety Administration
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49 CFR Parts 385, 390, and 395
Hours of Service of Drivers; Final Rule
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DEPARTMENT OF TRANSPORTATION
Federal Motor Carrier Safety Administration
49 CFR Parts 385, 390 and 395
[Docket No. FMCSA-2004-19608; formerly FMCSA-1997-2350]
RIN-2126-AA90
Hours of Service of Drivers
AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT.
ACTION: Final rule.
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SUMMARY: FMCSA is publishing today its final rule governing hours of
service for commercial motor vehicle drivers, following its Notice of
Proposed Rulemaking published January 24, 2005. The rule addresses
requirements for driving, duty, and off-duty time; a recovery period,
sleeper berth, and new requirements for short-haul drivers. The hours-
of-service regulations published on April 28, 2003, were vacated by the
U.S. Court of Appeals for the District of Columbia Circuit on July 16,
2004. Congress subsequently provided, through the Surface
Transportation Extension Act of 2004, that the 2003 regulations will
remain in effect until the effective date of a new final rule
addressing the issues raised by the court or September 30, 2005,
whichever occurs first. Today's rule meets that requirement.
DATES: This rule is effective October 1, 2005.
FOR FURTHER INFORMATION CONTACT: Tom Yager, Chief, Driver and Carrier
Operations Division, Office of Bus and Truck Standards and Operations
(MC-PSD), Federal Motor Carrier Safety Administration, 400 Seventh
Street. S.W., Washington, DC 20590. Phone 202-366-4009, E-mail <A href="mailto:MCPSD@fmcsa.dot.gov">
MCPSD@fmcsa.dot.gov</A>.
SUPPLEMENTARY INFORMATION:
Table of Contents
A. Legal Basis for the Rulemaking
B. Background Information
C. Executive Summary
D. Research Review Process
E. Driver Health
F. Driver Fatigue
G. Current and Future FMCSA Research
H. Crash Data
I. Operational Data
J. Comments to Docket and FMCSA Responses
J.1. Sleep Loss
J.2. Exposure to Environmental Stressors
J.3. Workplace Injuries and Fatalities
J.4. Lifestyle Choices
J.5. Driving Time
J.6. Duty Tour
J.7. Off-Duty Time
J.8. The 34-Hour Restart and 60/70-Hour Rules
J.9. Sleeper-Berth Use
J.10. Regulation of Short-Haul Operations
J.11. Combined Effects
J.12. Effective and Implementation Dates
J.13. Electronic On-Board Recording Devices
J.14. Other Provisions
J.15. Legal Issues
K. Rulemaking Analyses and Notices
K.1. Executive Order 12866 (Regulatory Planning and Review) and
DOT Regulatory Policies and Procedures
K.2. Regulatory Flexibility Act
K.3. Unfunded Mandates Reform Act of 1995
K.4. National Environmental Policy Act
K.5. Paperwork Reduction Act
K.6. Executive Order 13211 (Energy Supply, Distribution, or Use)
K.7. Executive Order 12898 (Environmental Justice)
K.8. Executive Order 13045 (Protection of Children)
K.9. Executive Order 12988 (Civil Justice Reform)
K.10. Executive Order 12630 (Taking of Private Property)
K.11. Executive Order 13132 (Federalism)
K.12. Executive Order 12372 (Intergovernmental Review)
L. List of References
Table of Abbreviations
AHAS Advocates for Highway and Auto Safety
AMI Acute Myocardial Infarction
AMSA American Moving and Storage Association
ANPRM Advance Notice of Proposed Rulemaking
APA Administrative Procedure Act
ATA American Trucking Associations
BAC Blood Alcohol Content
BLS U.S. Bureau of Labor Statistics
BMI Body Mass Index
CATF Clean Air Task Force
CDL Commercial Drivers License
CEQ Council on Environmental Quality
CFR Code of Federal Regulations
CHP California Highway Patrol
CMV Commercial Motor Vehicle
CRASH Citizens for Reliable and Safe Highways
CRMCA Colorado Ready Mixed Concrete Association
CTC Corporate Transportation Coalition
CVD Cardiovascular Disease
CVSA Commercial Vehicle Safety Alliance
dBA Decibels Adjusted
DE Diesel Exhaust
DOT Department of Transportation
EA Environmental Assessment
ECMT European Conference of Ministers of Transport
EEI Edison Electric Institute
EOBR Electronic On-Board Recorder
EPA U.S. Environmental Protection Agency
FARS Fatality Analysis Reporting System
FHWA Federal Highway Administration
FMCSA Federal Motor Carrier Safety Administration
FMCSR Federal Motor Carrier Safety Regulations
FMP Fatigue Management Program
FONSI Finding of No Significant Impact
FR Federal Register
GVWR Gross Vehicle Weight Rating
HEI Health Effects Institute
HOS Hours of Service
IBT International Brotherhood of Teamsters
ICC Interstate Commerce Commission
ICCTA ICC Termination Act of 1995
IIHS Insurance Institute for Highway Safety
IRP International Registration Plan
ISO International Standards Organization
LBP Lower Back Pain
LH Long Haul
LR Long Regional
LTL Less-Than-Truckload
MCMIS Motor Carrier Management Information System
MCSAP Motor Carrier Safety Assistance Program
MFCA Motor Freight Carriers Association
MPH Miles per Hour
MTA Minnesota Trucking Association
NACA National Armored Car Association
NAICS North American Industrial Classification System
NEPA National Environmental Policy Act
NHTSA National Highway Traffic Safety Administration
NIH National Institutes of Health
NIOSH National Institute for Occupational Safety and Health
NITL National Industrial Transportation League
NPRM Notice of Proposed Rulemaking
NPTC National Private Truck Council
NRMCA National Ready Mixed Concrete Association
NSSGA National Stone, Sand, and Gravel Association
NTSB National Transportation Safety Board
OMB Office of Management and Budget
OOIDA Owner-Operator Independent Drivers Association
OOS Out-of -Service
OSHA U.S. Occupational Safety and Health Administration
OTR Over-the-Road
PATT Parents Against Tired Truckers
PM Particulate Matter
PMC PubMed Central
PRA Paperwork Reduction Act of 1995
PVT Psychomotor Vigilance Test
RIA Regulatory Impact Analysis
RMA Risk Management Association
R&T Research and Technology
RODS Records of Duty Status
SBA Small Business Administration
SH Short Haul
SR Short Regional
STAA Surface Transportation Assistance Act
TCA Truckload Carriers Association
TIFA Trucks Involved in Fatal Accidents
TL Truckload
TOT Time-on-Task
TRB Transportation Research Board
UMTRI University of Michigan Transportation Research Institute
UPS United Parcel Service
USV Utility Service Vehicle
VIUS Vehicle Inventory and Use Survey
VMT Vehicle Miles Traveled
VSL Value of a Statistical Life
VTTI Virginia Tech Transportation Institute
WBV Whole Body Vibration
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A. Legal Basis for the Rulemaking
This rule is based on the authority of the Motor Carrier Act of
1935 and the Motor Carrier Safety Act of 1984.
The Motor Carrier Act of 1935 provides that ``The Secretary of
Transportation may prescribe requirements for--(1) qualifications and
maximum hours of service of employees of, and safety of operation and
equipment of, a motor carrier; and (2) qualifications and maximum hours
of service of employees of, and standards of equipment of, a motor
private carrier, when needed to promote safety of operation'' [49
U.S.C. 31502(b)].
The hours-of-service regulations adopted today deal directly with
the ``maximum hours of service of employees of * * * a motor carrier
[49 U.S.C. 31502(b)(1)] and the ``maximum hours of service of employees
of * * * a motor private carrier'' [49 U.S.C. 31502(b)(2)]. The
adoption and enforcement of such rules was specifically authorized by
the Motor Carrier Act of 1935. This rule rests squarely on that
authority.
The Motor Carrier Safety Act of 1984 provides concurrent authority
to regulate drivers, motor carriers, and vehicle equipment. It requires
the Secretary of Transportation to ``prescribe regulations on
commercial motor vehicle safety. The regulations shall prescribe
minimum safety standards for commercial motor vehicles.'' Although this
authority is very broad, the Act also includes specific requirements:
``At a minimum, the regulations shall ensure that--(1) Commercial motor
vehicles are maintained, equipped, loaded, and operated safely; (2) the
responsibilities imposed on operators of commercial motor vehicles do
not impair their ability to operate the vehicles safely; (3) the
physical condition of operators of commercial motor vehicles is
adequate to enable them to operate the vehicles safely; and (4) the
operation of commercial motor vehicles does not have a deleterious
effect on the physical condition of the operators'' [49 U.S.C.
31136(a)].
This rule is based on the authority of the 1984 Act and addresses
the specific mandates of 49 U.S.C. 31136(a)(2), (3), and (4). Section
31136(a)(1) of 49 U.S.C. deals almost entirely with the mechanical
condition of commercial motor vehicles (CMVs), a subject not included
in this rulemaking. The phrase ``operated safely'' in paragraph (a)(1)
refers primarily to the safe operation of the vehicle's equipment, but
to the extent it encompasses safe driving, this rule also addresses
that mandate. Before prescribing any regulations, FMCSA must also consider their
``costs and benefits'' [49 U.S.C. 31136(c)(2)(A) and 31502(d)]. Those
factors are also discussed later.
B. Background Information
B.1. History of the Hours-of-Service Rule
The Interstate Commerce Commission (ICC) promulgated the first
Federal hours-of-service regulations (HOS) in the late 1930s. The rules
were based on the Motor Carrier Act of 1935. The regulations remained
largely unchanged from 1940 until 2003, except for an important
amendment in 1962. Prior to 1962, driver hours-of-service regulations
were based on a 24-hour period from noon to noon or midnight to
midnight. A driver could be on duty no more than 15 hours in a 24-
consecutive-hour period. In 1962, among other rule changes, the 24-hour
cycle was removed and replaced by minimum off-duty periods. A driver
could ``restart'' the calculation of his or her driving and on-duty
limitations after any period of 8 or more hours off duty.
Section 408 of the ICC Termination Act of 1995 (ICCTA) (Pub. L.
104-88, 109 Stat. 803, at 958) required the Federal Highway
Administration (FHWA) to conduct rulemaking ``dealing with a variety of
fatigue-related issues pertaining to commercial motor vehicle safety.''
In response, FHWA published an advance notice of proposed rulemaking
(ANPRM) on November 5, 1996 (61 FR 57252). FMCSA was established as a
separate Agency on January 1, 2000. At that time, responsibility to
promulgate CMV regulations was transferred from FHWA to FMCSA, which
published an hours-of-service Notice of Proposed Rulemaking (NPRM) on
May 2, 2000 (65 FR 25540) and a final rule on April 28, 2003 (68 FR
22456). Technical amendments to the final rule were published on
September 30, 2003 (68 FR 56208). Motor carriers and drivers were
required to comply with the final rule on January 4, 2004.
FMCSA's 2003 rule did not change any hours-of-service requirements
for motor carriers and drivers operating passenger-carrying vehicles.
They were required to continue complying with the hours-of-service
rules existing before the 2003 rule (see 68 FR 22461-22462). Changes in
hours-of-service provisions in the new rule applied only to motor
carriers and drivers operating property-carrying vehicles. Compared to
the previous regulations, the 2003 rule: (1) Required drivers to take
10, instead of 8, consecutive hours off-duty (except when using sleeper
berths); (2) retained the prior prohibition on driving after 60 hours
on duty in 7 days or 70 hours in 8 days; (3) increased allowable
driving time from 10 to 11 hours in any one duty period; and (4)
replaced the so-called 15-hour rule (which prohibited drivers from
driving after being on duty more than 15 hours, not including
intervening off-duty time) with a 14-hour rule (which prohibited
driving after the 14th hour after the driver came on duty, with no
extensions for off-duty time). Note that the 15-hour limit had been
cumulative--so it could be interspersed with off-duty time--while the
non-extendable 14-hour limit was consecutive. Additionally, FMCSA
allowed drivers to ``restart'' the calculations for the 60- and 70-hour
limits by taking 34 consecutive hours off duty. Based on the data and
research available at the time, FMCSA was convinced that these new
rules constituted a significant improvement in the hours-of-service
regulations, compared to the rules they replaced, by providing drivers
with better opportunities to obtain off-duty time offering daily
restorative sleep, thereby reducing the incidence of crashes wholly or
partially attributable to drowsiness or fatigue.
On June 12, 2003, Public Citizen, Citizens for Reliable and Safe
Highways (CRASH) and Parents Against Tired Truckers (PATT) filed a
petition to review the new hours-of-service rule with the United States
Court of Appeals for the District of Columbia Circuit (D.C. Circuit).
On July 16, 2004, the D.C. Circuit issued an opinion holding that the
rule was arbitrary and capricious because the Agency failed to consider
the impact of the rules on the health of drivers, as required by 49
U.S.C. 31136(a)(4). Public Citizen et al. v. Federal Motor Carrier
Safety Administration, 374 F.3d 1209, at 1216. The D.C. Circuit noted,
however, that neither Public Citizen nor the court was ``suggest[ing]
that the statute requires the agency to protect driver health to the
exclusion of those other factors [i.e., the costs and benefits of the
rule], only that the agency must consider it.'' Id. at 1217 (emphasis
in original). Although FMCSA argued that the effect of driver health on
vehicle safety had permeated the entire rulemaking process, the court
said that driver health and vehicle safety were distinct factors that
must be considered separately.
In dicta the court also stated that: (1) FMCSA's justification for
increasing allowable driving time from 10 to 11 hours might be legally
inadequate because the Agency failed to show how additional off-duty
time compensated for more driving time, and especially
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because it failed to discuss the effects of the 34-hour recovery
provision; (2) splitting off-duty time in a sleeper berth into periods
of less than 10 hours was probably arbitrary and capricious, because
FMCSA itself asserted that drivers need 8 hours of uninterrupted sleep;
(3) failing to collect and analyze data on the costs and benefits of
requiring electronic on-board recording devices (EOBRs) probably
violated section 408 of the ICC Termination Act, which requires FMCSA
to ``deal with'' EOBRs; and (4) the Agency failed to address or justify
the additional on-duty and driving hours allowed by the 34-hour
recovery provision.
On September 1, 2004 (69 FR 53386), FMCSA published an ANPRM
requesting information about factors the Agency should consider in
developing performance specifications for EOBRs. As the Agency said in
the preamble to that document, ``FMCSA is attempting to evaluate the
suitability of EOBRs to demonstrate compliance with the enforcement of
the hours-of-service regulations, which in turn will have major
implications for the welfare of drivers and the safe operation of
commercial motor vehicles.'' The ANPRM asked for comments and
information, both on technical questions relating to EOBRs, and on the
potential costs and benefits of such devices. The EOBR rulemaking has
been and will remain separate from this hours-of-service rulemaking.
(For additional discussion of EOBRs, see Section J.13.)
On September 30, 2004, the President signed the Surface
Transportation Extension Act of 2004, Part V (Public Law 108-310, 118
Stat. 1144). Section 7(f) of the Act provides that ``[t]he hours-of-
service regulations applicable to property-carrying commercial drivers
contained in the Final Rule published on April 28, 2003 (68 FR 22456-
22517), as amended on September 30, 2003 (68 FR 56208-56212), and made
applicable to motor carriers and drivers on January 4, 2004, shall be
in effect until the earlier of--(1) the effective date of a new final
rule addressing the issues raised by the July 16, 2004, decision of the
United States Court of Appeals for the District of Columbia in Public
Citizen, et al. v. Federal Motor Carrier Safety Administration (No. 03-
1165); or (2) September 30, 2005.'' (118 Stat. at 1154).
B.2. Notice of Proposed Rulemaking (January 24, 2005)
FMCSA published an NPRM on January 24, 2005 (70 FR 3339) to
reconsider the 2003 rule and determine what changes might be necessary
to correct the deficiencies identified by the court. The Agency used
the 2003 rule as a proposal for the purpose of soliciting public
comments, but also announced that ``[t]his rulemaking is necessary to
develop hours-of-service regulations to replace those vacated by the
Court'' (70 FR 3342). The NPRM asked a series of questions on driver
health, sleep loss and deprivation, driving time, sleeper berths, and
other subjects; the answers are discussed later. While awaiting the
submission and review of docket comments, the Agency pursued a research
program to identify relevant studies on the same issues; the results of
that effort are also described in later sections of the preamble.
C. Executive Summary
Today's rule requires all drivers of property-carrying commercial
motor vehicles (CMVs) in interstate commerce to take at least 10
consecutive hours off duty before driving, limits driving time to 11
consecutive hours within a 14-hour, non-extendable window after coming
on duty, and prohibits driving after the driver has been on duty 60
hours in 7 consecutive days, or 70 hours in 8 consecutive days. Drivers
may restart the 60- or 70-hour ``clock'' by taking 34 consecutive hours
off duty.
These provisions are the same as those of FMCSA's 2003 final rule
that was vacated by the U.S. Court of Appeals for the D.C. Circuit and
then reinstated by Congress for the duration of fiscal year 2005. These
limits, however, are significantly different from the pre-2003 HOS
regulation, which required only 8 hours off duty before driving,
allowed 10 hours of driving time, and prohibited driving after having
been on duty for 15 hours (but allowed any off-duty time taken during
the work shift to be excluded from the calculation of the 15-hour
limit). The pre-2003 rule had no counterpart to today's 34-hour
recovery provision. The recovery role was played by the 60- and 70-hour
limits, the only element of the pre-2003 rule which has been adopted
without change for property-carrying vehicles in today's rule.
The 14-hour driving window and the 10-hour off-duty requirement of
today's rule combine to move most drivers toward a 24-hour cycle, which
allows the body to operate in accord with its normal circadian rhythm
and the driver to sleep on the same schedule each day. A driver may
remain on duty after the 14-hour window closes or go off duty after the
11th hour of driving, in each case returning to work after 10 hours off
duty on something other than a 24-hour cycle. Nonetheless, FMCSA
believes that most drivers, most of the time, will go off duty at or
before the end of the 14th hour, since their principal responsibility--
driving--is illegal after that point. The circadian friendliness of
today's rule is bolstered by the requirement for 10 consecutive hours
off duty. This is enough time to enable drivers to get the 7-8 hours of
sleep most people need to maintain alertness and prevent the onset of
cumulative fatigue.
The original restart provisions were the 60- and 70-hour limits.
Drivers could not drive after having been on duty for those periods
until they had been off duty long enough to reduce their 7- or 8-day
on-duty totals below the 60- or 70-hour threshold. These limits are
being adopted in today's rule, but the Agency is also adding a second
and more flexible recovery provision, as it did in 2003--the 34-hour
restart. A 34-hour period gives a large majority of drivers the
opportunity for two night sleep periods, and all drivers the
opportunity for two consecutive 8-hour sleep periods separated by a
full 18-hour day. Comments to the docket stated that the 34-hour
restart provides far more flexibility than the 60- and 70-hour limits
alone, enabling drivers to tailor their schedules to their business
requirements while still spending more time at home.
Today's rule also creates a new regulatory regime for drivers of
CMVs that do not require a CDL, provided they operate within a 150-mile
radius of their work-reporting location. These drivers are not required
to keep logbooks, though their employers must keep accurate time
records, and the driver may use a 16-hour driving window twice a week.
Driving time may not exceed the normal 11 hours, but the longer
operational window twice a week enables short-haul carriers to meet
unusual scheduling demands. Short-haul drivers rarely drive anything
close to 11 hours, and available statistics show that they are greatly
under-represented in fatigue-related accidents. On a per-mile basis,
long-haul trucks are almost 20 times more likely to be involved in a
fatigue-related crash. One study suggested that a contributing factor
to this statistical imbalance is the variety of work short-haul drivers
typically perform; variety seems to minimize fatigue.The rule adopted today balances considerations of driver and public
safety, driver health, and costs and benefits to the motor carrier
industry--all factors the Agency is required to take into account. The
provisions are described separately in the preamble, but they
constitute an interconnected whole and cannot be adequately understood
in isolation.
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The rule addresses driver health issues in detail, and provides a
lengthy explanation and justification for the requirements adopted
today. FMCSA has examined a wide range of scientific evidence,
independently collected, summarized, and reviewed by a health panel
created at the Agency's request by the Transportation Research Board of
the National Academies of Science. FMCSA has concluded that the
operation of CMVs under this rule does not have a deleterious effect on
the physical condition of drivers. Because relatively little of the
available evidence was derived from motor carrier operations, the
Agency had to evaluate and weigh information from different fields and
adapt it to a trucking environment. We believe our conclusions
accurately reflect a preponderance of the scientific data. The
additional off-duty time provided by the rule, along with the 14-hour
driving window, should have a particularly beneficial effect on
drivers' sleep opportunities, and indirectly on their health as well.
In an indication of the fatigue-reducing benefits of the 2003 rule,
preliminary information on sleep habits under that rule shows drivers
are getting, on average, at least an additional hour of sleep compared
to the pre-2003 rule. There is no indication that drivers are averaging
more hours of work, as opponents of the 2003 rule had feared.
The Agency has examined all of the data on crash risk. Virtually
every study has weaknesses or limitations. The largest database on
fatal truck crashes (Trucks Involved in Fatal Crashes, or TIFA) records
accidents that occurred entirely under the pre-2003 HOS rule, when off-
duty time could have been as short as 8 hours. Furthermore, while the
crash risk reflected in TIFA data rises with the number of hours driven
before the crash, the risk in the 11th hour generally reflects illegal
driving, since the normal limit at the time was 10 hours. Also, despite
being the largest database available, the data contain relatively few
fatigue-related crashes after long hours of driving. All in all, we
thus must be careful in applying this data to the 2003 rule or today's
rule, where the minimum off-duty time is 25 percent greater.
On the other hand, we also examined recent data collected while the
2003 rule was in effect. Although this data suggests that fatigue-
related crashes have fallen since the 2003 rule became effective, this
newer data is mostly preliminary, self-reported without statistical
controls, and also reflects small sample sizes, all of which--once
again--sometimes leads to inconsistent findings.
The rule and the Regulatory Impact Analysis discuss the strengths
and weaknesses of each data source and balance the shortcomings of one
against the advantages of another. The TIFA data from 1991 to 2002 are
very comprehensive. In order to ensure that its safety analysis erred
on the side of caution, the Agency used TIFA data to estimate the risk
of additional driving hours, knowing that the risk is probably over-
stated given the better opportunities for restorative sleep available
under the 2003 rule and today's final rule. It is also clear that newer
CMVs, with their quieter and more comfortable cabs, are less fatiguing
to drive. That change may also affect the usefulness of the TIFA data,
though this factor is impossible to quantify.
Using the most conservative estimates of crash risk for a given
amount of driving time, FMCSA's analysis shows that the safety
differential between a 10-hour and an 11-hour driving limit is very
small while the economic cost differential is very large. The
operational and scheduling flexibility of an 11-hour limit, even when
it is not utilized fully, is both economically and socially valuable.
According to the drivers who commented to the docket, the 11-hour limit
in the 2003 rule enables them to get home more often, when the 10-hour
limit would leave them stranded at roadside, out of hours. It also
allows them to get home without pushing quite as hard as they might be
tempted to do under a 10-hour limit.
FMCSA examined a range of options and found that today's rule is
the only one that is cost-beneficial, with a net annual benefit
estimated at $270 million. Reducing driving time from 11 to 10 hours,
while leaving the rest of today's rule intact, would increase net costs
by $526 million per year. To confirm our findings, we conducted a
sensitivity analysis of the data and assumptions used. We changed these
parameters in a way that was unfavorable to today's rule in general and
to allowing 11 hours of driving in particular. No parameters tested,
either singly or in combination, produced a basis for either replacing
the 11-hour driving limit with a 10-hour limit, or suggested that
another option could be more cost-beneficial.
D. Research Review Process
In preparing this final rule, FMCSA thoroughly, systematically, and
extensively researched both U.S. and international health and fatigue
studies and consulted with Federal safety and health experts. In
addition, FMCSA asked the Transportation Research Board (TRB) of the
National Academies to contract with a research team of experts in the
field of health and fatigue to prepare a summary of relevant literature
through the TRB Commercial Truck and Bus Safety Synthesis Program. The
literature review was conducted using two teams of health and
transportation experts to identify and summarize the available research
literature relevant to this HOS rulemaking. This review included
research findings that discussed in a scientific, experimental,
qualitative, and quantitative way the relationship between the hours a
commercial motor vehicle driver works, drives, and the structure of the
work schedule (on-duty/off-duty cycles, time-on-task, especially time
in continuous driving, sleep time, etc.), and the impact on his/her
health.
Dr. Peter Orris, M.D., Professor of Occupational Health at the
University of Illinois, led a team of six prominent medical doctors,
epidemiologists, and an ergonomist to identify relevant research on CMV
driver health. Dr. Alison Smiley, President of Human Factors North
Inc., Professor in the Department of Mechanical and Industrial
Engineering, University of Toronto, and the Department of Civil
Engineering, Ryerson University, led a team of three leading
transportation and fatigue experts to review relevant fatigue studies.
Each team conducted two literature reviews, a review of the literature
at the beginning of the project and a review of the literature that was
submitted by commenters to the 2005 NPRM. It was through this rigorous
process that FMCSA ensured that not only the latest research, but the
best available science was used to support this rulemaking. The final
reports are located in the docket and are entitled ``Literature Review
on Health and Fatigue Issues Associated with Commercial Motor Vehicle
Driver Hours of Work,'' Part I and Part II.
The driver health team used PubMed Central (PMC), which is the U.S.
National Institutes of Health (NIH) digital archive of biomedical and
life sciences journal literature. PMC includes MEDLINE, which is the
premier bibliographic database covering the fields of medicine,
nursing, dentistry, veterinary medicine, the health care system, and
the preclinical sciences. MEDLINE contains over 12 million
bibliographic citations dating back to the mid-1960s and author
abstracts from more than 4,800 biomedical journals published in the
United States and 70 other countries.
The initial driver health literature search from 1975 to present
resulted in
[[Page 49982]]
over a thousand research articles. The driver health team screened
these studies based on relevance to the topics of commercial vehicle
operator health and the health effects of work hours, shift work, and
sleep schedules. A total of 55 of the relevant studies were reviewed in
greater detail. Twenty-five were chosen and summarized by a primary
reviewer to be included in the Part I final report. The criteria for
inclusion were the validity of the methodology, the relevance of the
studied population to truck driving, and the quality of the statistical
analysis of health outcomes.
Similarly, the TRB driver fatigue team used the TRANSPORT database,
a bibliographic database of transportation research and economic
information produced by the 25-nation Organization for Economic Co-
operation and Development, together with the United States TRB, and the
31 nations of the European Conference of Ministers of Transport (ECMT).
TRANSPORT includes the Transportation Research Information Services,
International Road Research Documentation, and ECMT's TRANSDOC.
Collectively these sources contain over 530,000 citations from
publications, most with abstracts, of research information on all
surface transportation modes, air transport, and highway safety. The
driver fatigue team searched these studies for relevance concerning
hours of service, and CMV operator performance and fatigue. Because
FMCSA had previously docketed summaries of fatigue-related studies used
in preparing the 2003 rule, the scope of this literature review was
limited to studies published after 1995. Primary sources were selected
if they addressed truck driver performance (on road or simulated), and
included driving performance measures (vehicle control or critical
incidents). Only studies were selected which involved drivers on
typical work-rest schedules, involving extended hours of driving,
driving in a sleep-deprived state, and/or driving at night. After the
initial set of research reports was screened based on relevance, the
driver fatigue team reviewed a total of 26 relevant studies, and 13
were chosen to be summarized for the Part I report.
As a result of the questions posed in the 2005 NPRM, commenters
referenced over 200 studies. The driver health and fatigue teams
reviewed the titles and abstracts of studies referenced by commenters
using the identical criteria that were used for screening the initial
research discussed earlier. Articles considered most relevant were
those involving epidemiological studies, studies of CMV crash risk, or
field studies of performance of commercial drivers in relation to
fatigue issues such as daily and weekly hours, time of day, and short
sleep, or studies of non-CMV drivers showing the effects of sleep loss
and comparing sleep loss and alcohol impacts. The reasons for not
reviewing the remaining articles suggested by commenters included the
following: an article was not published as a report of a recognized
Agency or in a peer-reviewed journal; an article was very general in
nature (e.g. a discussion of circadian rhythm); or, an article was not
sufficiently relevant to the task of CMV driving. The driver health
team selected 11 of these studies to review and summarize for inclusion
in the Part II report, while the driver fatigue team selected 21
studies for the Part II report.
In addition to reviewing the studies mentioned above, FMCSA
internally reviewed, summarized, and evaluated research reports that
were previously cited in the 2003 rule, 2004 litigation, 2005 NPRM, and
driver fatigue and performance studies that were excluded from the TRB
literature review (i.e., published before 1996).
The Agency also assembled an intermodal team of experts on operator
fatigue and health to help FMCSA further identify and analyze relevant
research. The Federal agencies represented were the Federal Aviation
Administration, Federal Railroad Administration, U.S. Coast Guard, and
the National Institute for Occupational Safety and Health (NIOSH).
E. Driver Health
The D.C. Circuit held that FMCSA failed to consider the possibly
deleterious effect of the 2003 hours-of-service rule on the physical
condition of drivers, as required by 49 U.S.C. 31136(a)(4).
To assess driver health and better comprehend the impact of the
findings, one must understand the differences in the types of relevant
medical research. Epidemiology is the study of diseases in populations
of humans or animals, specifically how, when, and where they occur.
Epidemiology attempts to determine what factors are associated with
diseases (risk factors). Epidemiological studies can never prove
causation; that is, they cannot prove that a specific risk factor
actually causes the disease being studied. Epidemiological evidence can
only show that a risk factor is associated (correlated) with a higher
incidence of disease in the population exposed to that risk factor. The
higher the correlation the more certain the association, but it cannot
prove the causation.
Another type of study is a dose-response study. A dose-response
study is based on the principle that there is a relationship between a
toxic reaction (the response) and the amount of substance received (the
dose). Knowing the dose-response relationship is a necessary part of
understanding the cause and effect relationship between chemical
exposure and illness.
A third type of study is a case-control study, which investigates
the prior exposure of individuals with a particular health condition
and those without it to infer why certain subjects, the ``cases,''
become ill and others, the ``controls,'' do not. The main advantage of
the case-control study is that it enables the study of rare health
outcomes without having to track thousands of people. One primary
disadvantage of a case-control study is a greater potential for bias.
Because the health status is known before the exposure is determined,
the study does not allow for broader-based health assessment.
These are important distinctions for the following discussion of
the research on driver health, specifically regarding exposure to environmental stressors such as exhaust, chemicals, noise, and
vibration. FMCSA has reviewed and evaluated the available and pertinent
information concerning driver health, with emphasis on chronic
conditions potentially associated with changes from the pre-2003 and
2003 rules, to this final rule. The research on CMV driver health falls
into several broad categories: (1) Sleep loss/restriction, (2) exposure
to exhaust, (3) exposure to noise, (4) exposure to vibration, (5)
cardiovascular disease, (6) long work hours, and (7) shift work and
gastrointestinal disorders.
E.1. Sleep Loss/Restriction
The lack of adequate sleep has been shown to have detrimental
impacts on the overall health of humans. Research suggests that sleep
deprivation adversely affects human metabolism as well as the endocrine
and immune systems [Spiegel, K., et al. (1999), p. 1438]. Chronic
partial sleep loss is associated with decreased glucose tolerance,
decreased leptin levels, increases in evening cortisol levels, and
adverse cardiovascular effects [Spiegel, K., et al. (2004), p. 5770].
Consistent with these studies, epidemiologic research demonstrates that
short sleep duration is modestly associated with symptomatic diabetes
[Ayas, N. T. et al. (2003), p. 383], cardiovascular disease, and
mortality [Alvarez, G.G., & Ayas, N. T. (2004), p. 59]. Other studies
have shown that short sleepers (less than 6
[[Page 49983]]
hours) have hormone and metabolic changes which result in weight gain
[Hasler, G., et al. (2004), p. 661; Morikawa, Y., et al. (2003), p.
136; Taheri, S., et al. (2004), p. 210; Vioque, J., et al. (2000), p.
1683]. Interleukin 6 (IL-6) is a marker of systemic inflammation that
may lead to insulin resistance, cardiovascular disease, and
osteoporosis. Sleep loss of as little as two hours per night increases
daytime IL-6 and causes drowsiness and fatigue during the next day,
whereas post-deprivation decreases nighttime IL-6 and is associated
with deeper sleep [Vgontzas, A. N., et al. (2004), p. 2125].
As to the amount of sleep necessary, the National Sleep Foundation
recommends 8 hours per day. This standard comes primarily from studies
by the National Institutes of Health (NIH), which notes that this was
the mean time period that healthy young adults gravitated to when
external influences were removed. Not all sleep researchers agree with
this conclusion, particularly with regard to individual health and
well-being. Two large-scale studies have found no relationship between
longer sleep and better health [Kripke, D. F., et al. (2002), p. 131;
Patel, S. R., et al. (2004), p. 440]. The epidemiological research on
sleep duration suggests that mortality may even begin to rise with
sleep durations greater than 8 hours. Likewise, mortality risk
increases for short sleep durations less than 6 hours per day [Id.].
The research identified that prior to the 2003 HOS rule, CMV
drivers were not getting enough sleep (i.e., 7-8 hours per day) as
needed to maintain individual health. In four major research studies,
where sleep was verified using either an actigraph watch (wrist-worn
monitoring device) or electroencephalogram, CMV drivers averaged from
3.8 to 5.25 hours of sleep per day [Dinges, D. F., et al. (2005), p.
38; Balkin, T., et al. (2000), p. 4-48; Mitler, M. M., et al. (1997),
p. 755; Wylie, C. D., et al. (1996), p. ES-10]. These averages are
below the 6 to 8 hours of sleep that are associated with lower
mortality or a healthy lifestyle.
Preliminary data from the following sources suggest that, on
average, CMV drivers are obtaining more sleep than before under the
2003 rule, which requires at least 10 consecutive hours of off-duty
time. First, an ongoing joint National Highway Traffic Safety
Administration (NHTSA) and FMCSA study conducted in 2005 found that
drivers were averaging 6.28 hours of sleep per day, a figure that was
verified with an actigraph watch [Hanowski, R.J., et al. (2005), p.1].
Second, in a survey of its membership, the Owner-Operator Independent
Drivers Association (OOIDA) found that of the 1,264 drivers responding,
355 or 30 percent of drivers stated that they were getting more rest as
a result of the 2003 HOS rule with 10 consecutive hours of off-duty
time. The other 70 percent of the drivers responded that they were
getting either the same amount of rest or no additional rest was needed
as a result of the 2003 rule.
Comparing study findings before and after the 2003 HOS rule change
suggests that drivers are getting more than an hour of additional sleep
per night than they previously were able to obtain. While the Agency
would like to see drivers obtain a sleep period between 7 to 8 hours
per day to maximize driver alertness, the finding of 6.28 hours of
sleep per night is within normal ranges consistent with a healthy
lifestyle and is a vast improvement over previous sleep findings. Based
on the research that led to the 2003 final HOS rule, FMCSA knew that
short sleep (less than 6 hours) among drivers was a concern from both a
safety and health standpoint. As a result, FMCSA increased off-duty
time to 10 consecutive hours thereby increasing driver sleep by up to
an additional two hours per day. This final rule adopts the requirement
for the 10 consecutive hours of off-duty time.
E.2. Exposure to Diesel Exhaust
The Environmental Protection Agency's (EPA) Health Assessment
Document for Diesel Engine Exhaust (2002) concluded that ``long-term
(i.e., chronic) inhalation exposure is likely to pose a lung cancer
hazard to humans, as well as damage the lung in other ways depending on
exposure'' [EPA (2002), p. ii].
Diesel exhaust (DE) is not a single ``thing'' but a mixture of
hundreds of gases and particles, which differ with the type of engine
generating them, operating conditions, and fuel formulations. Some of
the components of DE are known carcinogens (e.g., benzene) and others
are mutagenic or toxic. Particulates from diesel engines, which
constitute about 6 percent of the total ambient particulate matter (PM)
with an aerodynamic diameter of 2.5 micrometers or less (PM-2.5), are
highly respirable and able to reach the deep lung. Yet EPA has not
formally declared DE to be a carcinogen. There are several reasons for
this ambiguity.
A dose/response curve is the classic means of measuring the effect
of exposure. A curve is typically established in a laboratory. Very
high doses are given over a relatively short period, and the
physiological response is measured. A dose/response curve is assumed to
be a straight line, which can be extended downward to the lower
exposures typical of ambient conditions outside the laboratory. If the
dose/response curve is not a straight line (because the physiological
response decreases disproportionately when exposure is reduced), the
curve will overstate the effect of ambient exposure by some unknown
amount. In that case, long-term population studies might be an
alternative, provided long-term exposure can be established.
Attempts to establish a dose/response curve for DE have not
produced clear-cut results. In animal studies, rats develop lung tumors
after lifetime inhalation of DE at exposures vastly higher than any
ambient condition; but these cancers appear to be at least partially
the result of particle overload, which prevents lung clearance and
causes chronic inflammation and subsequent lung disease. Chronic
inhalation studies in mice show equivocal results, and hamsters do not
develop cancer [Bunn, W.B., et al. (2002), p. S126; EPA (2002), p. 7-
139]. EPA therefore concluded that ``the rat lung tumor response is not
considered relevant to an evaluation of the potential for a human
environmental exposure-related hazard'' [Id.]. EPA further noted that
``[t]he gaseous phase of DE (filtered exhaust without particulate
fraction) was found not to be carcinogenic in rats, mice, or hamsters''
[Id.].
Although EPA has declared DE to be a ``probable human carcinogen,''
based in part on a review of 22 epidemiologic studies of workers
exposed to DE in various occupations, it also noted that the
``Increased lung cancer relative risks generally range from 1.2
to 1.5, though a few studies show relative risks as high as 2.6.
Statistically significant increases in pooled relative risk
estimates (1.33 to 1.47) from two independent meta-analyses further
support a positive relationship between DE exposure and lung cancer
in a variety of DE-exposed occupations. The generally small increase
in lung cancer relative risk (less than 2) observed in the
epidemiologic studies and meta-analyses tends to weaken the evidence
of causality. When a relative risk is less than 2, if confounding
factors (e.g., smoking, asbestos exposure) are having an effect on
the observed risk increases, they could be enough to account for the
increased risk'' [EPA (2002), pp. 7-138 and 7-139].
Overall, the evidence is not sufficient for DE to be considered a
proven human carcinogen because of exposure uncertainties (lack of
historical exposure data for workers exposed to DE) and an inability to
reach a full and direct accounting for all possible confounders [Id.].
[[Page 49984]]
The actual cancer risk involved in operating a diesel-engine truck
depends on the degree and duration of exposure to DE, and especially to
smaller particulate matter (PM-2.5). Information on the real-world DE
exposure of truck drivers is limited by many uncertainties. Because
trucks spend a great deal of time in motion, the exposure levels of
different highway, municipal, and regional environments have to be
collected and combined. Idling time at terminals, in traffic jams, or
while using a sleeper berth presumably generates higher exposure than
does highway driving, but estimating the possible combinations of
conditions for a large population of drivers is difficult. Furthermore,
because of the long latency period of most cancers, the extent of the
risk to truck drivers depends on the length of their exposure. This in
turn is influenced by the factors that existed several decades ago:
engine design, formulation of diesel fuel, prevalence of smoking among
driver populations, total particulate levels from all sources, etc. In
most cases, this information is less well known than comparable data on
these factors today. Nor can one project previous (assumed) conditions
forward or current conditions backward; virtually everything about DE
has been changing in the last few decades and will continue to change
as EPA tightens the regulations that govern diesel engine design and
diesel fuel. Also, given EPA initiatives to reduce truck idling, and
Federal financing available for idle-reduction programs, FMCSA expects
additional reductions in exposure of CMV drivers to DE.
Before discussing the studies reviewed by the driver health team,
it is useful to analyze a potential exposure effect of a feature of the
2003 rule, which is adopted in this final rule--the availability of
additional driving and on-duty hours through the use of the 34-hour
recovery provision. If utilized to the extreme, this would allow
another 17 hours of driving time and 24 hours of on-duty time in a 7-
day work week, compared to the limit of 60 hours of driving time
without the recovery provision. To examine the effect of the 2003 rule
on driver work hours, FMCSA compared an earlier survey of drivers
operating under the pre-2003 rule with a recently completed survey. In
a 7-day work week, the 451 drivers who responded to the earlier survey
worked, on average (driving and other on-duty time), 64.3 hours per
week [Campbell, K.L., & Belzer, M.H. (2000), p. 104]. In 2005, FMCSA
evaluated a sample of driver logs and determined that the 489 drivers
included, with a total of 5,397 7-day periods, worked an average of
61.4 hours (driving and other on-duty time) per week [FMCSA Field
Survey Report (2005), p. 4].
At the annual meeting of the TRB in Washington, D.C. in January
2005, Schneider National, a large motor carrier, provided a
distribution of the weekly (8-day period) on-duty hours for its drivers
(available in the docket for this rule). The data shows that
Schneider's employee drivers averaged 62 hours on duty per 8-day period
and its leased drivers averaged 65 hours on duty per 8-day period. In
addition, J.B. Hunt, another large motor carrier, in comments to the
NPRM, reviewed the work records of 80 randomly selected over-the-road
drivers for a 30-day period. J.B. Hunt found that 74 percent of its
drivers used the 34-hour restart at least once during the 30-day
period. On average, J.B. Hunt's drivers accumulated 62.25 hours on duty
per eight-day period. This data provides some indication of the hours worked as a result
of the 2003 rule. Given the data from surveys and comments regarding
work hours from motor carriers, it does not appear that CMV drivers are
working on average significantly more hours as a result of the 2003
rule as compared to the pre-2003 regulation. Consequently, based on
review of the data, the average exposure of drivers to DE has remained
essentially unchanged.
The driver health team identified and reviewed four studies that
address the issue of hours of work and duration of DE exposure in
transportation workers. A large case-control study in Germany found
significant associations between lung cancer and employment as a
professional driver. The risk reached statistical significance for
exposures longer than 30 years [Br[uuml]ske-Hohlfeld, I., et al.
(1999), p. 405]. An exposure response analysis and risk assessment of
lung cancer and DE found a 1 to 2 percent lifetime increased risk of
lung cancer above a background risk of 5 percent among workers in the
trucking industry, based on historical extrapolation of elemental
carbon levels [Steenland, K., et al. (1998), p. 220]. A large case-
control study of bus and tramway drivers in Copenhagen found a negative
association between lung cancer and increased years of employment
[Soll-Johanning, H., et al. (2003), p. 25]. Finally, a meta-analysis of
29 studies addressing occupational exposure to DE and lung cancer
showed that 21 of the 23 studies meeting the inclusion criteria,
observed relative risk estimates greater than one (probability of a CMV
driver developing lung cancer divided by the probability of the control
group developing lung cancer). A positive duration response was noted
in all studies that quantified exposure [Bhatia, R., et al. (1998), p.
84].
Several studies have shown an association between truck driving and
bladder cancer. The driver health team reviewed three studies that
addressed the association between duration of exposure to DE and
bladder cancer. A population-based case-control study in New Hampshire
found a positive association between bladder cancer and tractor-trailer
driving, as well as a positive trend with duration of employment [Colt,
J.S., et al. (2004), p. 759]. A large study in Finland found increased
standard incidence ratios for six types of cancer in truck drivers.
Cumulative exposure to DE was negatively associated with all cancers
except ovarian cancer in women with high cumulative exposure [Guo, J.,
et al. 2004, p. 286]. A meta-analysis of 29 studies on bladder cancer
and truck driving found an overall significant association between
``high'' exposure to DE and bladder cancer as well as a dose-response
trend. The authors concluded that DE exposure may result in bladder
cancer, but the effects of misclassification, publication bias, and
confounding variables could not be fully taken into account [Boffetta,
P., & Silverman, D.T. (2001), p. 125].
As a result of the number of studies showing an association, DE is
considered to be a ``probable'' carcinogen by the World Health
Organization and the U.S. Department of Health and Human Services'
National Toxicology Program. Because of the complexity of proving a
definitive link between DE and cancer, no organization, other than the
California EPA, has classified DE as a known carcinogen [Garshick, E.,
et al. (2003), p. 17]. Studies have a great degree of uncertainty due
to study design and exposure assumptions, measurement issues, and
synergistic effects of various pollutants, among other variables.
[Bailey, C.R., et al. (2003), p. 478]. Excluding rats, animal studies
are overall negative with regard to lung tumor formation following DE
exposure. In rats, lung tumors are produced by lifetime inhalation
exposure to many different particle types. These exposures are
characterized as ``lung overload;'' however, numerous analyses point to
a lack of relevance of data from lung-overloaded rats to human risk
calculations, particularly at environmental or ambient levels [Bunn,
W.B., et al. (2002), p. S122]. As noted earlier, EPA's risk assessment
on DE, based on long-term (chronic) exposure,
[[Page 49985]]
concludes that DE is ``likely to be carcinogenic to humans by
inhalation.'' Studies show a causal relationship between exposure to DE
and lung cancer, but EPA has not concluded that DE is a human
carcinogen and cannot develop a quantitative dose-response cancer risk.
The rat inhalation studies underpinning these findings resulted from
overloading DE and are unrealistic exposure scenarios for humans [Ris,
C. (2003), p. 35].
The acute (short-term) effects of DE, which would allow us to
determine safe exposure levels, are not currently known [Id.]. Also,
there are not enough human test data to make a definitive risk
assessment on the chronic long-term respiratory effects of DE. Tests on
animals, however, suggest chronic respiratory problems exist [Id.].
Cleaner burning diesel fuel standards (2006) combined with cleaner
diesel engine technologies from more stringent emission standards
(2007) will generate a net reduction in pollutant emissions, despite
growth in diesel use [Sawyer, R.F. (2003), p. 39].
EPA models project on a national basis the amount of emissions or
pollutants expected annually from all mobile sources. These are based
on estimates of vehicle miles traveled and new vehicles entering and
old vehicles leaving the inventory, and they reflect changes in vehicle
emissions standards. The models project emissions for the following
pollutants: Carbon Monoxide, Oxides of Nitrogen, Volatile Organic
Compounds, Particulate Matter (PM-2.5), Particulate Matter (PM-10), and
Sulfur Dioxide. EPA estimates show that vehicle emissions from all
mobile sources have declined significantly from 1990 to 2005 (average
35 percent reduction in emissions) and are projected to decline further
until 2030 (average 55 percent reduction in emissions). DE from heavy
vehicles represents about 23 percent of all emissions from mobile
sources. DE from heavy vehicles has also declined from 1990 to 2005
(average 55 percent reduction in emissions) and is projected to decline
further until 2030 (average 88 percent reduction in emissions). The
following chart shows the projections of heavy vehicle DE from the on-
the-road fleet by type of emission from 1990 to 2030. The chart is
based on U.S. EPA's ``National Annual Air Emissions Inventory for
Mobile Sources,'' which was conducted for a variety of pollutants
emitted by on-road vehicles. [EPA (January 2005)]. Mobile source
emission inventories were directly modeled for 2001, 2007, 2010, 2015,
2020, and 2030. Other years were obtained by linear interpolation.
EPA's Air Inventory was developed using the National Mobile Inventory
Model [EPA (March 2005)].
[GRAPHIC] [TIFF OMITTED] TR25AU05.000
If diesel or all engine emissions are in fact carcinogenic (not yet
proven), then the risk of developing cancer is a function of both the
amount of DE being inhaled and cumulative exposure (time). Based on EPA
emission projections of lower emissions from on-the-road heavy
vehicles, continued reduction in health impacts can be expected over
time.
It appears that chronic (long-term) exposure to DE may cause
cancer. The exposure/dose required, however, is currently unknown due
to the extreme difficulty in measuring and modeling exposure. EPA has
noted that there is great
``uncertainty regarding whether the health hazards identified from
previous studies using emissions from older engines can be applied
to present-day environmental emissions and related exposures, as
some physical and chemical characteristics of the emissions from
certain sources have changed over time. Available data are not
sufficient to provide definitive answers to this question because
changes in DE composition over time cannot be confidently
quantified, and the relationship between the DE components and the
mode(s) of action for DE toxicity is unclear'' [Ris, C. (2003), p.
35].
Some of those flaws might be addressed by Garshick's effort to
quantify lung cancer risk in the trucking industry through an
epidemiological study using up to 72,000 subjects [Garshick, E., et al.
(2002), p. 115]. At this time, however, according to EPA,
[[Page 49986]]
NIOSH, the Centers for Disease Control and Prevention, and NIH, there
is not enough evidence to declare DE a carcinogen. Nonetheless, EPA's
finding that DE is a probable carcinogen is a cause for concern. EPA
has therefore adopted new diesel engine performance requirements and
will by 2007 require refiners to produce low-sulphur fuel [66 FR 5002].
EPA's previous and forthcoming regulatory changes lead to a projection
of dramatically lower DE through 2030, which will greatly reduce any
health effects of DE exposure.
Still, the question remains whether today's rule, regarding
exposure to DE, ensures that ``the operation of commercial motor
vehicles does not have a deleterious effect on the physical condition''
of CMV drivers [49 U.S.C. 31136(a)(4)]. After reviewing all the studies
mentioned, there is no evidence that today's rule has a deleterious
effect. This is not to deny the possibility that DE may have some
impact on truck drivers. The Agency, however, cannot attempt to address
a problem without data on its extent and severity. The data on exposure
to DE is notoriously deficient. As Garshick and his colleagues noted,
``The ideal marker of DE exposure would be a single marker that
would be inexpensive, easy to measure, and clearly linked to the
source of diesel emissions. However, the reality is that DE is a
complex mixture, and in many real-life scenarios it may not be the
only important source of exposure to the individual particles and
gases that constitute DE. In addition, the mechanism of the health
effects and specific causal agents are uncertain. The best diesel
exposure marker is likely to be more complex and involve the
measurements of molecular organic tracers and elemental carbon. The
nature of the exposure assessment and marker chosen may also depend
on mechanism of health effect postulated, and may include
measurement of exhaust gases (such as ozone and nitrogen oxide) in
the setting of nonmalignant respiratory diseases. Although current
literature identifies DE as a health hazard, insight into a dose-
response relationship is limited by factors related to both cohort
selection and exposure assessment. The development of an exposure
model in the existing DE epidemiologic literature is hindered by a
lack of exposure measurements upon which an exposure model can be
developed, uncertainty regarding the best measurement or marker(s)
indicative of exposure, and uncertainty regarding historical
exposures'' [Garschick, E., et al. (2003), p. 21].
One of the best works to date on DE, lung cancer, and truck driving
is a series of studies by Steenland and his colleagues published
between 1990 and 1998. The abstract of the 1998 study concludes that,
``[r]egardless of assumptions about past exposure, all analyses
resulted in significant positive trends in lung cancer risk with
increasing cumulative exposure. A male truck driver exposed to 5
micrograms/m<SUP>3</SUP> of elemental carbon (a typical exposure in
1990, approximately five times urban background levels) would have a
lifetime excess risk of lung cancer of 1-2 percent above a background
risk of 5 percent.'' The difference between 1 percent and 2 percent is
obviously quite large, but the absence of a dose/response curve for DE
and uncertainties in the exposure data make greater precision
impossible.
In 1999, however, the Health Effects Institute (HEI), a non-profit
corporation chartered in 1980 to assess the health effects of
pollutants generated by motor vehicles and other sources, and supported
jointly by EPA and industry, found significant flaws even in the 1998
Steenland study. As summarized by Bunn et al. [Bunn, W.B., et al.
(2002), p. S127], the HEI found that the Steenland study ``quite likely
suffers from an inadequate latency period, making it completely
unsuitable for reaching any qualitative or quantitative conclusions
about the link between DE exposure and lung cancer.'' Furthermore, the
workers in the study were exposed to an inseparable mix of gasoline and
diesel fumes. ``Indeed, during the 1960s (the critical years of the
Steenland study from a latency perspective), diesel fuel represented
only 4-7 percent of the total fuel sales (cars and trucks). Moreover,
in the 1960s, gasoline-fueled vehicles had no after-treatment, so that
emissions from gasoline-fueled vehicles likely would have been
comparable to those from diesel vehicles'' [Id.].
Given the uncertain effects of exposure to DE, FMCSA could not
include this factor in any cost/benefit analysis for any regulatory
change it wished to consider. Some changes are beyond FMCSA's
authority. EPA has exclusive authority to set emission standards for
new trucks, and NHTSA has comparable jurisdiction over equipment
standards for new vehicles. FMCSA retains a degree of authority to
order the retrofitting of safety equipment to vehicles already in
service [see 49 CFR 1.73(g)], but it is unclear what CMV equipment, if
any, could be installed on the current fleet to reduce the driver's
exposure to DE. A driver's ability to open one or both side windows
could defeat any air-cleaning technology that might be added to the
tractor, and all drivers spend time outside the vehicle at terminals,
truck stops, and other locations where exposure to DE is unavoidable.
Another possible means of reducing drivers' DE exposure would be to
curtail driving and on-duty time, or even to limit a driver's career to
a certain number of years, all in the interest of improved health. As
indicated above, however, there is no dose/response curve for DE and
the Agency could not be sure that a given reduction in hours or years
of service would produce a clear benefit. Forced retirement after a
certain number of years on the job is especially problematical. There
is nothing in the legislative history of 49 U.S.C. 31136(a)(4) to
indicate that Congress wanted FMCSA to protect the health of drivers by
limiting their livelihood. A limit on driving or on-duty hours for the
specific purpose of reducing DE exposure seems unnecessary, because the
available evidence shows that drivers have not increased their driving
or on-duty time in response to the 2003 rule.
One of the benefits of the 2003 HOS rule has been that it limits
driver duty periods to 14 consecutive hours per day with no extensions
for intervening off-duty periods. Under the pre-2003 rule, drivers were
allowed a 15-cumulative-hour duty period but could extend their maximum
duty period indefinitely by taking off-duty time during their workday.
This perpetuated the problem of excessive waiting time for pick up and
delivery of freight at shippers and receivers, because the drivers were
expected to place themselves in off-duty status while waiting. A 1999
study of dry freight truckload carriers by the Truckload Carriers
Association (TCA) revealed that drivers spent nearly seven hours
waiting for each freight shipment that they picked up and delivered.
The non-extendable 14-hour provision of the 2003 rule has given
motor carriers greater leverage to insist that shippers and receivers
reduce waiting time. At the 2005 Annual Meeting of the Transportation
Research Board (TRB) in January 2005, in Washington, DC, several large
carriers stated that as a result of the 14-hour rule, they are
increasingly charging detention fees when shippers and receivers cause
delays. As a result of the 14-hour provision, shippers and receivers
have had to improve the efficiency and productivity of loading docks.
Many drivers have commented that waiting time has been significantly
reduced. Reduced waiting time has a positive impact on drivers. First,
it reduces the total duty period for the driver, and reduces
unproductive and often uncompensated time. Second, loading docks were
cited by Garshick [Garshick, E. et al. (2003), pp. 24-25] as having
high levels of DE particulate
[[Page 49987]]
matter. Thus, reduced waiting time reduces driver exposure to DE and
could have beneficial impacts on driver health.
Diesel emissions have been falling steadily since the early 1990s
and will continue to decline for many years to come. To whatever
unknown extent DE may cause lung cancer, EPA's long-range regulatory
program is expected to reduce that risk. Three recent developments may
accelerate that downward trend. The first is the cost of diesel fuel,
which makes idling more expensive. The second is the spread of local
regulations that limit CMV engine idling time. The third is the
proliferation of truck-stop services available to drivers that
eliminate idling by providing hot or cold air for the sleeper berth,
cable TV, and internet access through an attachment to the side window
of the tractor. The expected reduction in engine idling in the next few
years should amplify the health and environmental benefits of EPA's
regulations. FMCSA has thus concluded that, while DE probably entails
some risk to drivers, after a thorough review of the data available, it
is the Agency's best judgment that, compared to the pre-2003 rule,
today's rule neither causes nor exacerbates that risk.
E.3. Exposure to Noise
The Occupational Safety and Health Administration (OSHA) noise
exposure standard for the workplace for unprotected ears is 90 decibels
adjusted (dBA) limited to 8 hours per day (29 CFR 1910.95). FMCSA also
has adopted a 90 dBA noise standard (49 CFR 393.94). Twenty-five
percent of the work force in the United States is regularly exposed to
potentially damaging noise [Suter, A.H., & von Gierke, H.E. (1987), p.
188]. In 1995, the FHWA Office of Motor Carriers conducted a study of
noise in CMVs. The study showed that noise levels in CMV cabs as
reported over the previous 25 years (1970-1995) had decreased
[Robinson, G.S., et al. (1997), p. 36]. The following table summarizes
noise findings from several studies:
Figure 2.--CMV Cab Noise Levels Documented From Several Studies
----------------------------------------------------------------------------------------------------------------
Model year (<GREEK-I> of
Study (year) trucks) dBA
----------------------------------------------------------------------------------------------------------------
Enone (1970)............................ 1960s era (4)................... >100 dBA.
Morrison & Clark (1972)................. 1960s era (16).................. 85-90 dBA.
Hessel (1982)........................... 1972-1977 (8)................... 74-87 dBA.
Reif & Moore (1983)..................... 1968-1978 (58).................. 85-90 dBA.
Morrison (1993)......................... 1993 (4)........................ < 80 dBA.
Micheal (1995).......................... 1995 (6)........................ < 80 dBA.
Van den Heever (1996)................... 1995 (16)....................... 83 dBA.
Robinson (1997) 1..................... 1990-95 (9)..................... 89 dBA.
Seshagiri (1998) 1.................... 400 measurements................ 83+ dBA.
----------------------------------------------------------------------------------------------------------------
Note 1: Study findings added to the table reported by Robinson (1997).
The truck-cab noise levels for nine trucks Robinson et al.
evaluated were found to be 89.1 dBA for eight conditions of highway
driving. This was very close to the FMCSA permissible exposure limit of
90 dBA. A sound dosimeter 1 was used to determine the noise doses
experienced by 10 truck drivers during normal commercial runs of 8 to
18 hours. The noise doses were measured with rest breaks, meal breaks,
and refueling breaks included, so they represented realistic
projections of actual truck trip noise doses experienced by drivers.
Robinson et al. also conducted pre- and post-workday audiograms for a
group of 10 drivers. Those results indicated that CMV drivers suffered
no temporary hearing loss after a normal driving shift.
---------------------------------------------------------------------------
1 A sound dosimeter is an instrument used to measure exposure
to sound.
---------------------------------------------------------------------------
In a more recent study of tractors of different models, makes, and
ages operating on routes that covered different types of Canadian
terrain, noise exposure was measured (over 400 measurements) under
several conditions. The noise level recorded ranged from 78 to 89 dBA,
with a mean of 82.7 dBA. The noise levels increased by 2.8 dBA with the
radio on, 1.3 dBA with the driver's side window open, 3.9 dBA with both
the window open and radio on, and 1.6 dBA for operations on four-lane
highways. Cab-over-engine vehicles appeared to be quieter than
conventional tractors by about 2.6 dBA. Long-haul (city to city)
operations on hilly terrain appeared to be quieter than on flat terrain
by about 2.2 dBA, probably indicating the strong effect of speed (tire,
wind, and engine noise). These researchers found conditions where CMVs
exceeded the Canadian noise limit of 85 dBA, mainly when the radio was
on and the driver's side window open [Seshagiri, B. (1998), p. 205].
In its comments to the docket, the American Trucking Associations
(ATA) reported that modern tractors usually have dBA levels ``in the
low 70's'' and that a ``typical Class 8 sleeper tractor cruising at 60
mph on level ground pulling a load will have a sound pressure level of
about 69-73 dBA.''
The research discussed earlier suggests cab noise levels are well
within FMCSA's 90-dBA noise standard. The noise levels documented have
not been shown to exceed OSHA or FMCSA standards. Therefore, the noise
levels in CMVs should not result in significant hearing loss over a
lifetime of on-the-job exposure, even if drivers drove the maximum
hours allowed by this final rule.
E.4. Exposure to Vibration
Exposure to whole body vibration (WBV) is believed to cause
fatigue, insomnia, headache, and ``shakiness'' shortly after or during
exposure. After daily exposure over a number of years, WBV can affect
the entire body and may result in a number of health disorders.
Occupational exposure to WBV may contribute to circulatory, bowel,
respiratory, muscular, and back disorders. The combined effects of body
posture, postural fatigue, dietary habits, long hours, and loading and
unloading are the possible other causes for these disorders.
Vibration in CMVs is a function of the age and maintenance of the
vehicle, speed, type of roadway, and driving behavior and performance;
and the most important variable is the condition of the roadway. There
are no vehicle manufacturing or operational standards for the control
of WBV, either in this country or abroad. The medical and research
communities use the 1997 International Standards Organization (ISO)
2631-1 guidelines for evaluating WBV.
[[Page 49988]]
Teschke conducted a thorough review of the research on WBV and back
disorders (including over 99 studies). This research found a number of
potential risk factors associated with lower back pain (LBP). Besides
WBV, the study identified a number of other confounding variables that
are associated with lower back pain. The following risk factors have
been found identified in the review of research in this area: (1)
Driver's age, (2) working postures, (3) repeated lifting and heavy
lifting, (4) smoking, (5) previous back pain, (6) falls or other
injury-causing events, (7) stress-related factors including job
satisfaction and control, and (8) body condition and morphology
including weight, height, physical condition, and body type [Teschke,
K., et al. (1999), p. 7]. The number of potential risk factors and
confounding variables makes it difficult to isolate the effects of WBV,
or even to conclude that WBV is the cause of lower back pain.
A recent study of volunteer drivers at a large transport company in
Canada found that operators were not on average at increased risk of
health effects from daily exposure when compared to the ISO guidelines.
The study did, however, find several instances where drivers in a 10-
hour shift were exposed to WBV levels established in an earlier ISO
standard. These instances were highly correlated to road conditions
[Cann, A.P., et al. (2004), p. 1432]. One of the criticisms of this
study was that vibration was measured at the floor or base of the
driver's seat, and measurements did not take into account the
attenuation of vibration by the driver's seat. Most seats in CMVs today
are air suspended to better isolate the driver from vibration.
Much of the WBV research is based on self-reporting through surveys
and questionnaires to identify factors that are associated with lower
back pain and back problems. For instance, a questionnaire study of bus
and truck drivers in Vermont and one in Sweden found a significant
association between long-term vibration dose and low back pain
[Magnusson, M.L., et al. (1996), p. 710]. Another questionnaire survey
in the Netherlands found significant associations between vibration and
low back pain as well as a significant dose-response [Boshuizen, H.C.,
et al. (1990), p. 109]. A recent review of the health literature on WBV
and lower back pain (LBP) concluded that, while ``there is probably an
association between WBV and LBP,'' there was no evidence of dose-
response [Lings, S. & Leboeuf-Yde, C. (2000), p. 290].
Studies addressing musculoskeletal disorders in truck drivers by
and large evaluate the effects of WBV. A questionnaire survey of
Japanese truck drivers found short resting time and irregular duty time
to be significant risk factors for lower back pain. It also found
positive but insignificant associations with long driving time per day
and week, but the hours classified as long were not specified
[Miyamoto, M., et al. (2000), p. 186]. A study of knee pain in taxi
drivers found a significantly increased risk of knee pain in workers
with more than 10 hours of daily driving. A significant dose-response
trend was also seen [Chen, J.C., et al. (2004), p. 575].
Our review of the literature on WBV and its potential health
effects, such as low back syndrome, is inconclusive because the studies
rely primarily on self-reporting and application of risks derived from
other environments. The literature related to commercial driving and
other musculoskeletal disorders suffers from the same limitations. A
causative relationship can only be viewed as suggestive within this
context.
The studies that tested vibration in CMVs found that vibration was
close to the ISO health risk threshold, but it did not consistently
exceed the threshold. The introduction of new trucks, which reduce the
driver's exposure to WBV, would be expected to mitigate any potential
effects of vibration. ATA submitted comments to the docket that modern
truck cabs are much quieter, are well ventilated, and have well
designed, efficient heating and air conditioning units. Physical stress
on drivers, including road vibration, is reduced by power steering.
Many trucks are also equipped with automatic transmissions, further
reducing stress. Improved suspension gives the driver a better ride,
and provides better handling. ATA maintained that the comfort and
safety improvements in truck tractors improve the driver's conditions,
leading to a reduction in stress and fatigue. Two carriers also
commented that modern trucks have greatly reduced noise and vibration.
Much of the research on whole body vibration within a CMV and its
effects on lower back pain or musculoskeletal disorders was based on
subjective measures and only weak associations have been found. Given
all the other confounding factors that have been shown to be associated
with these conditions (age, postures, lifting, smoking, falls, job
satisfaction, and body condition, including weight) it is highly
unlikely that vibration is the cause of LBP or musculoskeletal
disorders. The few studies of more objective measures of vibration have
not shown vibration to be, on average, above the health risk level
(with ISO standard).
When comparing the 2003 HOS rule to today's rule, it is the
Agency's best judgment that, based on the studies reviewed and comments
received, WBV does not pose a significant health risk to CMV drivers.
E.5. Cardiovascular Disease
Cardiovascular disease (CVD), principally heart disease and stroke,
is the nation's leading killer for both men and women among all racial
and ethnic groups. Almost one million Americans die of CVD each year--
42 percent of all deaths. CVD does not kill just the elderly--it is
also the leading cause of death for all Americans age 35 and older.
More than 16 percent of the deaths due to CVD are individuals 35 to 64
years old. The causes of CVD are complex. The following table
identifies some of the known risk factors:
Figure 3.--Risk Factors for Cardiovascular Disease
----------------------------------------------------------------------------------------------------------------
Individual factors Occupational factors Lifestyle factors
----------------------------------------------------------------------------------------------------------------
Genes
Age Sedentary Work Smoking
Gender Working Long Hours Alcohol/Drug Use
High Cholesterol Work Stress Sedentary Lifestyle
Amino Acid--Homocysteine Exposure to Physical Stressors and Lack of Exercise
Injuries
High Blood Pressure Shift Work Stress
Obesity .................................... Short Sleep
Diabetes
----------------------------------------------------------------------------------------------------------------
Source: American Heart Association.
[[Page 49989]]
The NIOSH representative to FMCSA's health group reviewed the
literature regarding CMV driving and the risk of developing CVD. Since
1992, a number of population research studies from Sweden and Denmark
have presented data suggesting an association between driving and CVD.
In contrast to occupational studies undertaken in the United States,
these research studies did not attempt to quantify ``hours of service
driving a truck'' or ``occupational chemical and particulate
exposures.'' Thus, these studies provide no data that could be used to
correlate individual or group ``exposures'' and CVD outcomes. No
studies conducted in the United States were found that permitted
examination of long hours of driving among truck drivers and the
possible association with CVD.
Swedish and Danish population studies provide support for the
hypothesis that driving occupations have elevated risks for
cardiovascular disease. Among drivers, Swedish population studies
indicate the greatest risk elevations occur among bus drivers, with
relative risks ranging from 50 percent to 114 percent in excess of
comparison populations [Bigert, C., et al. (2003), p. 333]. The
greatest risk ratio reported for truck drivers (a relative risk of
1.66), was reduced to 1.10 following statistical adjustment for
competing health and disease risk factors. A recent study suggests that
truck drivers experience no more than a 14 percent elevated risk
[Bigert, C., et al. (2004), p. 987].
Most epidemiologists take a fairly rigorous view of relative risk
values. In observational studies, results are not normally accepted as
significant if a relative risk ratio is less than 3 and is never
accepted if the relative risk ratio is less than 2 [Brignell, J.
(2005)]. In epidemiologic research, increases in risk of less than 100
percent are considered small and are usually difficult to interpret.
Such increases may be due to chance, statistical bias, or the effects
of confounding factors that are sometimes not evident.
A number of Japanese hospital record studies have examined the
association between long hours of work (not hours of driving) and acute
myocardial infarction (AMI). The most recent study suggests that weekly
work time in excess of 60 hours is related to increased risk of AMI
[Liu, Y., & Tanaka, H. (2002), p. 447]. This research suggests a two-
fold increased risk for overtime work (crude risk of 2.1, reduced to
1.81 after statistical adjustment for competing health and disease risk
factors). The authors conclude that overtime work and insufficient
sleep may be related to the risk of AMI.
Research is under way at NIOSH to evaluate mortality risk of
independent truck drivers in the United States. However, this study is
not designed to collect data on hours of service and other CVD risk
factors.
FMCSA's NIOSH representative concluded that current research
suggests the presence of only a weak association between CVD and truck
driving. Additionally, CVD is associated with many other occupational
types. No research studies were found that permitted an examination of
whether additional hours of driving a CMV impacts driver health as
measured by increased CVD or AMI. After thoroughly reviewing the
collective data, in the Agency's best judgment, based on the research
available, nothing implicates today's HOS rule in a heightened risk of
CVD or AMI.
Any increased risk of CVD or AMI may be mitigated by the increased
off-duty time (10 hours off duty) as well as the increase in
stabilization from the pre-2003 rule to the 2003 and today's rule of
the drivers' schedules (circadian rhythm). Changes implemented in truck
cab design, reducing exposure to exhaust, whole body vibration, and
noise may also mitigate the risk of CVD and AMI as well.
E.6. Long Work Hours
The average number of hours worked in the United States annually
has increased over the past several decades and currently surpasses
most countries in Western Europe and Japan [Caruso, C.C., et al.
(2004), p. 1]. Worker health and safety is a growing area of concern,
and thus more attention is being placed on whether there should be
limits on hours of work--similar to the hours of service regulations
for CMV drivers. The primary question being asked is whether there are
more adverse health consequences as a result of longer hours of work.
Beyond the previous study mentioned regarding CVD and long hours
[Liu, Y., & Tanaka, H. (2002), p. 447], the driver health team was able
to find only one other study that met their selection criteria and was
directly related to CMV drivers and long work hours [Jansen, N.W.H., et
al. (2003), p. 664]. This study focused on employees from 45 companies
in the Netherlands. Self-administered questionnaire data from 12,095
employees of the Maastricht Cohort Study on Fatigue at Work were used.
The researchers concluded that employees needed greater recovery
because their recovery scores (subjective measure of the self-perceived
need for rest) were significantly elevated in those working 9 to 10
hours per day, more than 40 hours per week, and frequent overtime
[Id.].
The lack of research literature on driver work hours required the
driver health team to expand its literature review into occupations
other than transportation workers. Particularly useful was a study
published by NIOSH in April 2004 entitled ``Overtime and Extended Work
Shifts: Recent Findings on Illnesses, Injuries, and Health Behaviors''
[Caruso, C.C., et al. (2004)]. The NIOSH report documents published
research on long work hours (greater than 8 hours work per day) and an
extended work week (greater than 40 hours per week).
The NIOSH review generally concluded that long work hours appear to
be associated with poorer health, increased injury rates, more
illnesses, or increased mortality. NIOSH found that individuals working
long hours generally have greater risk of unhealthy weight gain,
increased alcohol use, increased smoking, increased health complaints,
increased injuries while working, poorer neuropsychological
performance, reduced vigilance on task measures, reduced cognitive
function, reduced overall job performance, slower work, and decreased
alertness and increased fatigue, particularly in the 9th to 12th hours
of work. The adequacy of these study findings is addressed later in
this section of the preamble.
The NIOSH review examined the relationship between hypertension (a
risk factor for CVD) and long hours. It concluded that the research
findings regarding hypertension were inconsistent. Park [Park, J., et
al. (2001), p. 244] found no correlation between the hours worked by
Korean engineers, whose work hours during the previous month ranged
from an average of 52 hours to a high of 89 hours per week, and
increased hypertension. This study is relevant because the work-hour
limits are reasonably close to the limits a CMV driver could work under
this final rule.
CMV drivers, on average, work slightly more than 60 hours per week,
but FMCSA operational data show they rarely reach the maximum of 84
work hours per week. This number of work hours is beyond the typical
number of work hours examined by the research in the NIOSH review. The
NIOSH review did, however, examine three studies that identified the
relationship between very long shifts and immune function or
performance. Nakano [Nakano, Y., et al. (1998), p. 32] reported better
immune function in taxi drivers who were allowed to work overtime as
compared with drivers having work-hour
[[Page 49990]]
restrictions. This study examined taxi drivers working 48-hour or
longer shifts in 1992 and again in 1993. Leonard [Leonard, C., et al.
(1998), p. 22] reported declines in two tests of alertness and
concentration in medical residents who had worked 32-hour on-call
shifts. They reported no significant declines in a test of psychomotor
performance or a test of memory. A survey of anesthesiologists linked
long working hours to self-reported clinical errors [Gander, P.H., et
al. (2000), p. 178].
Two studies in the NIOSH review identified the relationship between
long hours and compensation. Siu and Donald [Siu, O.L., & Donald, I.
(1995), p. 30] and van der Hulst and Geurts [van der Hulst, M., &
Geurts, S. (2001), p. 227] suggested that compensation may reduce
adverse effects of long work hours. Siu and Donald [Siu, O.L., &
Donald, I. (1995), p. 31] reported a relationship between perceived
health status and overtime pay. Men from Hong Kong who received no
payment for overtime reported more health complaints when compared with men who received payment. In addition, van der Hulst and Geurts
examined the relationship between reward and long working hours in
Dutch postal workers. Rewards included salary, job security, and career
opportunities. They reported that high pressure to work overtime in
combination with low rewards was associated with a three-fold increase
in the odds for somatic complaints as compared with a reference
category of low overtime pressure in combination with high rewards.
Alternatively, high pressure in combination with high rewards did not
differ from the reference category. [van der Hulst, M., & Geurts, S.
(2001), p. 227] This research suggests that if workers are adequately
compensated for their time, they are less likely to have health
complaints. This is an important variable that can play a significant
factor in conducting subjective types of research on the effects of
long work hours and health. It also raises concerns regarding most
subjective data regarding the health consequences of long hours that do
not look at compensation as a factor.
With regard to the relationship between long work hours and worker
health, the NIOSH review concluded that ``research questions remain
about the ways overtime and extended work shifts influence health and
safety. Few studies have examined how the number of hours worked per
week, shift work, shift length, the degree of control over one's work
schedule, compensation for overtime, and other characteristics of work
schedules interact and relate to health and safety. Few studies have
examined how long working hours influence health and safety outcomes in
older workers, women, persons with pre-existing health problems, and
workers with hazardous occupational exposures.''
The NIOSH review of the literature on long work hours documents a
significant lack of data on general health effects. NIOSH reported that
even when looking at fatigue and accidents, identifying ``differences
between 8-hour and 12-hour shifts [is] difficult because of the
inconsistencies in the types of work schedules examined across studies.
Work schedules differed by the time of day (i.e., day, evening, night),
fixed versus rotating schedules, speed of rotation, direction of
rotation, number of hours worked per week, number of consecutive days
worked, number of rest days, and number of weekends off'' [Caruso,
C.C., et al. (2004), p. IV].
Additionally, van der Hulst conducted a review of 27 recent
empirical studies of long work hours [van der Hulst, M. (2003), p.
171]. He showed that long work hours are associated with some adverse
health outcomes as measured by several indicators (CVD, diabetes,
disability retirement, subjectively reported physical health,
subjective fatigue). He concluded, however, ``that the evidence
regarding long work hours and poor health is inconclusive because many
of the studies reviewed did not control for potential confounders. Due
to the gaps in the current evidence and the methodological shortcomings
of the studies in the review, further research is needed.''
The driver health team found very little research to evaluate
specifically the association between long work hours and CMV driver
health. No research studies were found that permitted an examination of
whether additional hours of driving or non-driving time would impact
driver health. Research on other occupations is mixed and does not show
conclusively that long hours alone adversely affect worker health.
Also, FMCSA's 2005 survey of driver hours indicates that the 2003 rule
has not increased the overall number of hours a driver actually works
(see Section I.1). Overall, this rule improves driver health compared
to the pre-2003 and 2003 rules through a combination of provisions (see
discussion of Combined Effects, Section J.11). The Agency has adopted
the non-extendable 14-hour driving window and the 10-hour off-duty
requirement; these provisions shorten the driving window allowed before
2003 by one hour (or more, in some cases) and lengthen the off-duty
period by two hours. In short, based on current knowledge and the
limited research that is available, in the Agency's best judgment there
is no evidence that the number of work hours allowed by the HOS
regulation adopted today will have any negative impact on driver
health.
E.7. Shift Work and Gastrointestinal Disorders
The term ``shift work'' covers a wide variety of work schedules and
implies that shifts rotate or change according to a set schedule. These
shifts can be either continuous, running 24 hours per day, 7 days per
week, or semi-continuous, running 2 or 3 shifts per day with or without
weekends. Workers take turns working on all shifts that are part of a
particular system. Shift work is a reality for about 25 percent of U.S.
workers. Similarly, 22 percent of CMV drivers work between the hours of
12 p.m. and 6 a.m. [Campbell, K.L., & Belzer, M.H. (2000), p. 115].
This final rule is intended to make work schedules more regular by
adhering more closely to a 24-hour clock than the pre-2003 rule. It
increases the number of consecutive off-duty hours to 10 and provides
for a non-extendable daily driving window of 14 hours. The pre-2003
rule provided only 8 hours of consecutive off-duty time and prohibited
driving after a cumulative total of 15 hours on duty per day. Under
that rule, however, drivers could extend the 15-hour limit by taking
off-duty time. Today's rule should provide some health benefits to CMV
drivers, because, as previously shown, drivers are getting more
consecutive hours of sleep and will generally adhere more closely to a
24-hour clock (14 hours on-duty and 10 hours off-duty = 24 hours).
By minimizing on-duty time and maximizing driving time, however, a
driver could operate on a backward rotating 21-hour schedule (11 hours
driving and 10 hours off duty = 21 hours). Although drivers might
conceivably employ that schedule, data suggests drivers do so only
rarely. Even when it does occur, this schedule is still beneficially
closer to 24 hours than the pre-2003 rule, which allowed a backward
rotating 18-hour work day (10 hours driving and 8 hours off duty = 18
hours).
The driver health team examined research on the health effects of
disrupting the circadian rhythm. The circadian rhythm spans about a
twenty-four-hour day, exemplified by the normal sleep-waking cycle.
Circadian rhythms in humans originate from a clock circuit in the
hypothalamus that is set by information from the optic nerve
[[Page 49991]]
about whether it is day or night. One of the earliest studies and most
definitive works in the area of shift work by Taylor and Pocock showed
no relationship between shift work and mortality [Taylor, P.J., &
Pocock, S.J. (1972), p. 201]. Two recent studies used experimental
conditions to evaluate the impact of an altered circadian rhythm on
insulin secretion. The first [Morgan, L., et al. (1998), p. 449] found
a longer sleep-wake cycle, such as might occur in rotating shift work,
to be associated with increased insulin resistance and glucose
response. In the second study, 261 shift workers completed a Standard
Shift Work survey in an investigation of health and well-being [Barton,
J., & Folkard, S. (1993), p. 59]. Workers using a forward rotating
schedule were more likely to complain of digestive and cardiovascular
disorders than those on a backward rotating system. This finding is
counterintuitive because most fatigue and shift work research suggests
that a forward rotating schedule is better from a sleep and fatigue
standpoint. The authors concluded that the combination of direction of
rotation and length of break when changing from one shift to another
may be a critical factor in the health and well-being of shift workers
[Id., p. 63].
In a thorough review of the literature on shift work and health up
to 1999, Scott [Scott, A.J. (2000), p. 1057] concluded that
gastrointestinal, CVD, and reproductive dysfunctions are more common in
shift workers, and that these effects may be due to rotating or fixed
shifts, number of nights worked consecutively, predictability of
schedule, and length of shift and starting time. Exacerbation of
medical conditions such as diabetes, epilepsy, and psychiatric
disorders, as well as the diseases noted above, may occur due to sleep
deprivation and circadian rhythm disruption. It should be noted,
however, that individuals with these conditions would not generally be
qualified to drive under FMCSA's medical standards.
In a more recent study, Ingre and Akerstedt [Ingre, M., &
Akerstedt, T. (2004), p. 45] investigated the effects of lifetime
accumulated night work based on monozygotic (from a single egg) twins.
The authors studied 169 pairs of twins where one of the two twins
worked night shifts while the other twin worked day shifts. The
subjects were all over 65 years old and retired. The study found no
significant difference between education, weight, body mass index
(BMI), diurnal or circadian rhythm, habitual rise times, habitual bed
times, and sleep times. The study found that the twin exposed to night
work was significantly more likely than the twin exposed to day work to
report lower ratings of subjective health (17.8% versus 10.7% who
stated that their health was poor). The study did not look at objective
measures of health. The most significant finding was how similar the
twins remained and that shift work did not adversely affect important
health measures (such as BMI, weight, sleep habits).
The general consensus in the shift work research community
therefore is that while certain work schedules may result in health
problems, there are few epidemiological studies of shift workers, and
more empirical data is needed. Furthermore, no aspect of the 2003 rule
or this final rule promotes the use of shift work within the
transportation industry. FMCSA knows that some drivers will drive at
night because of backward rotations of schedules or as a result of
their preference to drive at night. The rule is ``shift-neutral'' with
regard to driving during the daytime or nighttime. Therefore, in the
Agency's best judgment, this final rule should pose no greater risk to
driver health than the pre-2003 and 2003 rules with respect to shift
work. By promoting 24-hour cycles, today's rule should, in point of
fact, aid driver health in regard to shift work.
E.8. Efforts to Improve CMV Driver Health
Recognizing the important role that driver health and wellness play
in driver safety, performance, job satisfaction, and industry
productivity, FMCSA began a research project in May 1997 to design,
develop, and evaluate a model truck and bus wellness program. The
results of the research led to the creation of the ``Gettin'' in Gear''
program to create heightened awareness of and interest in driver health
and wellness. Materials from this program were distributed within the
truck and bus industry and provided basic health, nutrition, and
fitness information to CMV drivers. The ``Gettin'' in Gear'' program
was found to have a positive health impact on drivers who participated
in the program, both initially and when the Agency followed-up with
participants [Roberts, S., & York, J. (1999), pp. 15-28]. This was
shown in both lifestyle habits (e.g., exercising, resting, eating
balanced meals) and physical data (e.g., body mass index; pulse;
diastolic blood pressure; aerobic, strength, and fitness levels).
In addition, FMCSA has assessed the prevalence of sleep apnea among
CMV drivers and the safety impacts of this condition. FMCSA is
currently working with the National Sleep Foundation to develop an
education and outreach program to inform the motor carrier industry of
the problem of sleep apnea and how it can be effectively addressed.
E.9. Driver Health Summary
Today's rule provides for 10 hours of consecutive off-duty time,
giving drivers the opportunity to obtain 7 to 8 hours of restorative
sleep per day. Research on the implementation of the 2003 rule shows
that drivers are sleeping 6.28 hours of verified sleep and this is
within normal ranges consistent with a healthy lifestyle. Actually, the
data shows that, compared to pre-2003, drivers are on average sleeping
more than an hour longer per day.
On the issue of exposure, FMCSA has not found any evidence that
drivers are working significantly longer hours as a result of
implementation of the 2003 HOS rule, although it would be permissive.
While exposure to diesel exhaust may pose a cancer risk, no definitive
link has been yet established. Without a definitive link it is
impossible to determine the actual risk or estimate the societal costs
of DE to CMV drivers' health. However, based on EPA estimates of lower
emissions (starting in 1990 and continuing until 2030), and the fact
that drivers do not appear to be working longer hours, the Agency
believes that any potential health risk to CMV drivers already has been
reduced and will be reduced more in the coming years.
The noise levels documented in the research have not been shown to
exceed OSHA or FMCSA standards. Therefore, the noise levels in CMVs
should not result in a significant risk of hearing loss. The studies
that tested vibration in CMVs found that on average vibration was close
to the ISO health risk threshold, but it did not consistently exceed
the threshold. Changes in CMV cabs, diesel fuel, and engine designs
appear to have greatly reduced any potential health risks associated
with CMV driving. These changes have reduced drivers' exposure to
diesel exhaust, vibration, and noise. The research has shown that
exposure to these stressors do not to pose a significant health risk to
CMV drivers.
The research suggests the presence of only a weak association
between CVD and truck driving. No research studies were found that
permitted an examination of whether additional hours of driving a CMV
impacts driver health as measured by increased cardiovascular disease
or myocardial infarction. In the Agency's best judgment, based on the
research available, nothing implicates today's
[[Page 49992]]
HOS rule in a heightened risk of CVD or AMI.
The research on long hours and driver health is very limited.
Research on other occupations is mixed and does not show conclusively
that long hours alone adversely affect worker health. Also, FMCSA has
not found any evidence that drivers are working significantly longer
hours as a result of the 2003 rule. Therefore, the Agency has concluded
that there is no clear evidence that the number of work hours allowed
by the HOS regulation will have any impact on driver health.
While it is generally believed that shift work may result in health
problems, there are few epidemiological studies conducted on shift
workers. The most definitive research of shift work and health showed
no relationship between shift work and worker mortality. A recent study
of twins suggests that shift work does not alter important health
measures (such as BMI, weight, and sleep). Regardless, today's rule is
``shift-neutral'' with regard to driving during the daytime or
nighttime. Therefore, as previously stated, in the Agency's best
judgment this final rule should pose no greater risk to driver health
with respect to shift work.
F. Driver Fatigue
Over the past decade FMCSA has been conducting research and
reviewing the literature on driver fatigue in support of its effort to
revise the Agency's HOS regulations. In preparing this final rule,
FMCSA internally reviewed and evaluated numerous research reports that
were published prior to 1995. The TRB driver fatigue team already
mentioned conducted a literature review to identify studies concerning
hours of service and CMV driver performance and fatigue published after
1995. Additionally, the driver fatigue team reviewed additional studies
that were referenced in the comments to the 2005 NPRM. The pertinent
information from all these reviews was used in guiding the development
of this rule and is discussed in context under the relevant provisions
in Section J of this preamble. This section provides a discussion of
driver fatigue research relevant to the various provisions finalized in
today's rule. The following subsections will discuss research on: (1)
Issues related to driver fatigue (2) Circadian influences (3) Driving,
duty, and off-duty times, (4) Split-sleep, (5) Recovery, and (6) Short
haul. In addition, the Agency's current and future fatigue research
activities are discussed in Section G of this preamble.
F.1. Issues Related To Driver Fatigue
This regulation addresses the phenomenon of driver fatigue, i.e.,
the partial and at times total loss of alertness resulting from
insufficient quantity or quality of sleep. Sleep plays a critical role
in restoring mental and physical function, as well as in maintaining
general health. For most healthy adults, 7 to 8 hours of sleep per 24
hour period appears to be sufficient to avoid detrimental effects on
waking functions. Young adults, for example, report sleeping an average
of 7.5 hours per night during the week and 8.5 during the weekend
[Carskadon, M.A., & Dement, W.C. (2005), p. 18]. In a laboratory study
that compared the performance of two groups of subjects that spent 7
and 9 hours in bed, respectively, performance improved throughout the
study. With 7 hours in bed, impaired performance was only found on the
more sensitive tasks [Balkin, T., et al. (2000), p. ES-8]. Time in bed
does not necessarily equate to time asleep; and time asleep does not
always equate to quality sleep. For example, eight hours in bed is not
likely to yield the same restorative benefit for someone with a sleep
disorder or someone sleeping in a noisy, hot/cold, or otherwise
uncomfortable environment, as it does for a ``normal'' sleeper. Studies
of shiftworkers show that a given number of hours of sleep obtained
during the late morning (waking hours) does not yield the equivalent
amount of restorative sleep as the same number of hours obtained during
the late night/early morning (sleeping) hours [Monk, T. H. (2005), p.
676].
F.2. Circadian Influences
Humans ``are biologically wired to be active during the day and
sleepy at night'' [Monk, T. (2005), p. 674]. We have a homeostatic
drive to sleep that interacts with the circadian cycle [Van Dongen,
H.P.A., & Dinges, D.F. (2005), p. 440]. It has been well established
that mental alertness and physical energy rise and fall at specific
times during the circadian cycle, reaching lowest levels between
midnight and 6 a.m., with, for some people, a lesser but still
pronounced dip in energy and alertness between noon and 6 p.m. [Van
Dongen, H.P.A., & Dinges, D.F. (2005), p. 439]. To stay alert
throughout one's waking period, especially during these circadian
troughs, most adults require 7 to 8 hours of quality sleep per day.
Sleep obtained during the daylight hours of the circadian cycle is
generally of poorer quality than sleep obtained during the nighttime/
early morning ``sleeping hours.'' Working/driving during the ``third
shift'' (midnight to 6 a.m.) has the combined effect of affording
poorer quality daytime sleep, while requiring the driver to work/drive
during times when the physiological drive for sleep is strongest.
Changes of two or more hours in sleep/wake times cause one to become
out of phase with the circadian cycle. This disrupts the
synchronization of behavioral and biological processes (e.g., cognitive
performance, sleep, digestion, and body temperature), often resulting
in increased fatigue and performance decrements. Circadian de-
synchronization results from irregular or rotating shifts, especially
those that are not anchored to a 24-hour day (i.e., that start and end
at different times each day), resulting in poor quality sleep and
leading to accumulated fatigue. Backward rotating shifts that start an
hour or more earlier each day also cause one to become out of sync with
the circadian cycle, restricting sleep and leading to cumulative
fatigue. ``Forward rotating shifts--starting at a later time each day--
are not as good as a non-rotating shift, but are more compatible with
the properties of the circadian system than are backward-rotating
shifts.'' [Czeisler, C.A., et al. (1982), p. 462]. The importance of
maintaining a 24-hour day was highlighted in the 1998 HOS expert panel
report [Belenky, G., et al. (1998), p. 5].
The effects of the circadian cycle on driver alertness are
addressed in this final rule in the 14-hour maximum on-duty and 10-hour
minimum off-duty provisions (see Sections J.6 and J.7), which move
drivers closer to a 24-hour day, while allowing some scheduling
flexibility. This rule is far better than the pre-2003 HOS rule which
allowed a backward-rotating schedule of 18 hours per day. Being more
closely aligned to a 24-hour circadian cycle will allow drivers to
obtain better rest, mitigate driver fatigue, and improve CMV safety.
F.3. Driving, Duty, and Off-Duty Times
A review of the past and current research provides support for
adopting a maximum 14-hour driving window, which, when combined with
the 10 hours off-duty provision, helps maintain a 24-hour clock
(circadian cycle) and provides enough time for most drivers to obtain
adequate sleep before returning to work.
Two studies that assess the length of driving time have been
conducted since the 2003 rule went into effect.
One is an analysis of data from an on-road field test of a drowsy
driver-monitoring device. The study monitored, among other things,
driver
[[Page 49993]]
sleep quantity and the number of critical incidents (e.g., crashes,
near-crashes, and evasive actions) in which the driver became involved,
and assessed driver fatigue and performance during critical incidents.
Analysis of the study data, which were collected from May 2004 to May
2005, found that drivers included in the study were sleeping an average
of 6.28 hours under the 2003 rule, which requires at least 10 hours off
duty. For drivers who drove in both the 10th and 11th hour, no
significant difference was found between the 10th and 11th hours of
driving with respect to either alertness or involvement in critical
events [Hanowski, R.J., et al. (2005), p. 9]. A similar but pre-2003
on-road study [Wylie, C.D., et al. (1996), p. ES-9] with 80 long-haul
drivers who drove either 10 (U.S. rule) or 13 hours (Canadian rule)
found that drivers were averaging 5.18 hours sleep per night. Both the
Canadian and U.S. HOS rules that were in effect at the time required a
minimum 8 hours off duty. Thus, comparing these two studies, drivers
working under the 10-hour minimum off-duty rule are averaging over 1
hour more sleep per night. In the Wylie, et al. [Id.] study, there was
no difference in the amount of drowsiness observed in video records
(for comparable daytime segments) between the 10-hour and the 13-hour
driving times. Self-rating of fatigue increased with driving duration
even though there were no strong performance changes, leading the
authors to conclude, ``Time on task was not a strong or consistent
predictor of observed fatigue'' [Wylie, C.D., et al. (1996), page ES-
9].
Another study under the pre-2003 rule, ``Trucks Involved in Fatal
Accidents'' (TIFA) [Campbell, K.L. (2005)], found an increase in crash/
fatality risk with increasing driving time. This study included only
data on crashes that occurred from 1991 to 2002, prior to the 2003 HOS
rule change. Additionally, among the 50,000 trucks involved in fatal
crashes that occurred over the 12-year period, only nine crashes
involving drivers who drove in the 11th hour of driving were fatigue-
related. Note that these drivers were probably driving illegally, since
the pre-2003 rule had a 10-hour driving limit.
A recent study [Jovanis, P.P., et al., (2005)] used time-based
logistic regression models to develop crash risk estimates by hours of
driving. While all drivers drive during the first hour of the trip,
relatively few drive through the 11th hour. Therefore, the sample sizes
in the 11th hour of driving are typically so small that the resulting
model has a large standard error, particularly at the upper limits of
the driving time. As a result, the model's 95 percent confidence
intervals in the crash risk estimates for the 11th hour of driving show
that the crash risk could be significantly higher than driving in the
first hour, or it could be just slightly elevated above the first hour
of driving. The most likely cause for this inconclusive result is small
sample size.2
---------------------------------------------------------------------------
2 Statistical estimates based on small sample sizes tend to
have large sampling variations, meaning that detecting statistically
significant differences between two estimates may not be possible.
---------------------------------------------------------------------------
Sleepiness, performance decrements and crash risk follow the
circadian cycle, that is, they peak in the late afternoon at one of the
circadian low points [Wylie, C.D., et al. (1996), pp. 1-3; Akerstedt,
T. (1997), p. 106]. This fact emphasizes the value of moving toward a
24-hour work/rest day. The 14-hour maximum driving window, combined
with the 10-consecutive-hour minimum off-duty time provided in today's
rule, moves toward stabilizing the 24-hour clock by helping to avoid
driver shift rotation, and providing enough time to obtain 7-8 hours of
sleep for most drivers. Rotating shifts that advance or delay the
starting time for each subsequent shift can cause drivers to become out
of phase with their circadian rhythm, depending on the extent of the
change in their starting time. The 14-hour driving window and 10-hour
off-duty time provisions of this final rule provide an opportunity to
maintain a 24-hour work/rest day that will allow drivers to maintain
circadian rhythm. FMCSA analysis indicates that approximately 22
percent of CMV drivers drive during the early morning hours (midnight
to 6 a.m.). These drivers will benefit from the 10-hour minimum off-
duty provision in order to maximize their sleep time.
Longer daytime work hours combined with good quality and quantity
of sleep (7-8 hours) per day do not appear to pose a safety or health
problem to CMV drivers. In a driving simulator study, the schedule of
14 hours on duty/10 hours off duty for a 5-day week did not appear to
produce significant cumulative fatigue over the three-week study period
[O'Neill, T.R., et al. (1999), p. 2].
In Wylie, et al. [Id.] and other studies, the authors point out
that many of the drivers showed signs of, or reported, fatigue early in
the workweek after their ``weekend'' off-duty period [Morrow, P.C., &
Crum, M.R. (2004), p. 14; Hanowski, R.J., et al. (2000), p.17; Wylie,
C.D., et al. (1996), p. ES-9], implying that sleep habits on non-work
days are likely a significant contributor to driver fatigue. FMCSA
regulations can provide an opportunity for sleep, but drivers need to
maintain responsible sleeping habits.
Lin and his colleagues formulated an elapsed time-dependent
logistic regression model to assess the safety of motor carrier
operations [Lin, T.D., et al. (1993), p. 2]. Using crash data, this
model provides estimates of the probability of CMVs having a crash. The
estimates indicate that increased driving time had the strongest direct
effect on crash risk. All of the data for these estimates were obtained
from a single-less-than-truckload motor carrier. This study has many of
the same problems associated with the time-based logistic regression
models mentioned earlier; i.e., small sample size in the later hours of
driving. The authors concluded that crash risks ``are particularly
disturbing at 8th hour of driving. Unfortunately this is when
mathematical structure of the model becomes less certain * * * it
weakens our conviction to recommend reducing driver hours regulations''
[Lin, T.D., et al. (1993), p. 10]. Understanding the limitations of
their models, these authors did not recommend reducing driving time.
They did, however, recommend increasing the minimum off-duty time from
8 hours to 10 hours.
The research findings associated with driving time are conflicting.
The research on the effects of fatigue in operational (on-road) and
simulated/laboratory settings generally have found no statistically
significant difference in driver drowsiness or performance between the
10th and 11th hours of driving. The research analyzing crash data by
time of day are typically conducted with small sample sizes,
particularly in the 10th and 11th hours of driving, and the driver
samples are arguably not representative of the whole industry. These
studies generally find increasing risk with longer driving hours. On-
road/simulator studies, however, have found no increase in fatigue or
critical incidents while driving as many as 11 or as many as 13 hours
per day. The Agency regards the research on driving time as
inconclusive. FMCSA is adopting an 11-hour driving limit for the
reasons given in sections H and J.5. The data on off-duty time is less
problematical. Drivers appear to be obtaining more sleep as a result of
the 10-consecutive-hour off-duty provision in the 2003 rule. The Agency
has therefore decided to adopt a 10-hour off-duty requirement for CMV
drivers, coupled with a 14-hour driving window. This will move CMV
drivers toward a more-stable 24-hour clock. Because there is a good
deal of evidence that hours of continuous wakefulness
[[Page 49994]]
are a better predictor of fatigue than driving time, a 14-hour non-
extendable driving window will help to reduce driver fatigue, compared
to the extendable 15-hour window included in the pre-2003 rule. See
Sections H.6 and J.5 through J.7 for a more detailed discussion of the
Agency's findings and decisions regarding driving, duty, and off-duty
times.
F.4. Split Sleep
In the 2003 rule, drivers using trucks equipped with sleeper berths
were allowed to split their 10-hour off-duty/sleep time into two
periods of varying length as long as the shorter of the two periods was
a minimum of two hours. This exception to the 10-consecutive-hours off-
duty rule had, in many instances, resulted in drivers splitting their
sleep into two periods. Drivers could, for example, divide their sleep
over two 5-hour periods. The National Transportation Safety Board
(NTSB) has been critical of the split sleep provision in the past,
noting that, ``* * * sleep accumulated in short time blocks is less
refreshing than sleep accumulated in one long time period'' [NTSB
(1996), p. 46)].
Sleep becomes fragmented when drivers elect to take their sleep in
two shorter periods, rather than one 7 to 8 hour period. Fragmented
sleep has less recuperative value and has been shown to be similar to
partial sleep deprivation in its effects on performance [Belenky, G.,
et al. (1994), p. 129]. Studies of truck crash fatalities indicate that
split sleep taken by drivers has an adverse effect on CMV safety. In a
study of heavy truck crashes and accidents, NTSB cited police accident
reports that show decrements in performance occurring earlier for
drivers using sleeper berths. NTSB also found that ``drivers using
sleeper berths had a higher crash risk than drivers obtaining sleep in
a bed.'' NTSB reported that ``split-shift sleeper berth use increases
the risk of fatality more than two-fold;'' and ``[s]plit-sleep patterns
are among the top three predictors of fatigue-related accidents'' [NTSB
(1996), p. 46]. In summary, NTSB concluded that accumulating 8 hours of
rest in two sleeper-berth shifts increases the risk of fatality to
tractor-trailer drivers who are involved in crashes.
An earlier study by the Insurance Institute for Highway Safety
(IIHS) examined the association between sleeper berth use in two
periods and tractor-trailer driver fatalities [Hertz, R.P. (1988)]. The
findings from this study were similar to those reported by the NTSB.
The IIHS found that, ``* * * split-shift sleeper berth use (driving
without an eight-hour consecutive rest period), increased the risk of
fatality over twofold;'' and that, ``* * * split-shift sleeper berth
use increased the risk of fatality in all analyses except those limited
to urban crashes and local pick-up and delivery crashes'' [Id., p. 7].
The results of this analysis also found that accumulating 8 hours of
rest over two sleeper berth periods increases the risk of fatality to
tractor-trailer drivers who are involved in crashes. IIHS further
concludes ``[t]he fact that risk remained the same regardless of team
status suggests that increased risk of fatality is associated with
nonconsecutive sleep rather than disturbance from the motion of the
truck while sleeping'' [Id., p. 11].
Today's rule is based on the research cited and addresses the
concerns about driver fatigue resulting from sleep fragmentation by
requiring a consecutive 8-hour sleeper berth period to allow drivers to
obtain one primary period of sleep and a second 2-hour off-duty or
sleeper berth period to be used at the driver's discretion for breaks,
naps, meals, and other personal matters. The new sleeper berth
provision is fully described in Section J.9 of this preamble.
F.5. Recovery
Sleep restriction over several days leads to a degradation in
alertness and driving performance. When sleep is restricted by extended
duty periods or night work, cumulative fatigue occurs and an extended
off-duty period is needed to recover. Past studies have indicated that
a large percentage of drivers (commercial and noncommercial) get less
than the commonly recommended 7 to 8 hours sleep per day. [Dinges,
D.F., et al. (2005), p. 38; Balkin, T., et al. (2000), p. 4-48; Mitler,
M.M., et al. (1997), p. 755; Wylie, C.D., et al. (1996), p. ES-10].
Many drivers who obtain less than their daily requirement of sleep over
time incur a sleep debt; the resulting cumulative fatigue leads to an
increased crash risk [Hanowski, R.J., et al. (2000), pp. 11-12].
Recovery time is required to restore the mind and body to normal
function and health, as well as to erase the deleterious effects that
sleep loss has on alertness and performance.
The TRB fatigue team found five studies that provided information
regarding the recovery time needed for CMV drivers after working a long
week. Four of these studies provide support for recovery periods of 34
hours or less while only one of these studies supports a recovery
period longer than 34 hours.
Two studies suggest that a single 24-hour period is sufficient time
for a driver to recover from any cumulative fatigue. Alluisi's research
[Alluisi, E.A. (1972), p. 199] involved subjects who worked 8 hours a
day for 3 days, followed by a 4 hours on/4 hours off schedule (similar
to driving with a sleeper berth) over a 2-day period. He found that the
average performance of drivers dropped to 67 percent of baseline toward
the end of this period. A 24-hour rest period was sufficient to permit
recovery back to baseline. A simulator study examined daytime driving
of 14 hours on/10 hours off over a 15-day period [O'Neill, T.R., et al.
(1999), p. 36]. These authors found that 24 hours was an adequate
amount of time for recovery. A third study [Feyer, A.M., et al. (1997),
p. 541] found a dramatic recovery with respect to fatigue in team
drivers who stopped overnight in the middle of a 4 to 5 day trip. Thus,
with less than 24 hours off, a single night of sleep was very helpful
for recovery. A fourth study [Balkin, T., et al. (2000), p. 1-2] found
that whether or not 24 hours was sufficient depended on the sensitivity
of the performance measure used to assess recovery. Subjects who
carried out performance tasks during the day and were restricted to 3,
5, or 7 hours in bed at night were fully recovered after 1 day of
recovery sleep of 8 hours in bed, if the performance measure was lane
tracking or simulator driving crashes. If the measure was performance
on the psychomotor vigilance test (PVT), a more sensitive test of
fatigue, then recovery required more than 24 hours. The group who had 9
hours in bed during the work period, but were then restricted to 8
hours in bed during the recovery period, did not perform well on lane-
tracking as well as during the work period, clearly illustrating how
sensitive and essential one's performance is to even one additional
hour of sleep.
The TRB driver fatigue team found two recovery studies that were
conducted with CMV drivers in a field environment. The Wylie [Wylie,
C.D., et al. (1997)] study was a small demonstration study of a
methodology that could be used to evaluate drivers' recovery periods.
Twenty-five drivers were assigned into small groups (four to five
drivers) and were used to evaluate different recovery (12-, 36-, and
48-hour) periods and driving time. None of the recovery periods
examined were found to be of sufficient length for driver recovery.
However, the study concluded that the small subject sample limited the
ability to make reliable estimates of observed effects [Wylie, C.D., et
al. (1997), p. 27].
The methodology and sample size nullifies Wylie study findings, and
the
[[Page 49995]]
Agency has not relied on this study in determining the appropriate
recovery period for CMV drivers. Balkin [Balkin, T., et al. (2000), p.
5-1] as discussed in the previous section, found that after 7 days of
daytime work, when sleep had been restricted to 5 or 7 hours in bed, a
recovery period of more than 24 hours was required to return to
baseline levels of the most sensitive performance task. For extreme
sleep restriction of 3 hours in bed, 72 hours recovery was insufficient
to bring performance of the PVT task back to baseline.
While the research on driver recovery appears limited to five
studies that particularly focus on CMV driver recovery, two simulator
studies suggest that 24 hours is sufficient for recovery after 70 hours
of daytime driving [O'Neill, T.R., et al. (1999), p. 2; Alluisi, E.A.
(1972), p. 199]. One on-the-road study found that drivers achieve
adequate recovery after 24 hours off duty. Another on-road study
suggests that 36 hours is not quite sufficient with regard to PVT
measures, but is adequate for driving parameters, including lane-
tracking performance during daytime driving.
In balance, most of the research with CMV drivers supports the
assessment that a recovery period of 34 consecutive hours is sufficient
for recovery from moderate cumulative fatigue. The importance of two
night (10 p.m.-6 a.m.) recovery periods was highlighted by the 1998 HOS
expert panel report [Belenky, G., et al. (1998), p. 13]. The majority
of drivers (approximately 80 percent) are daytime drivers, and would
likely start their recovery period between 6 p.m. and midnight. All of
these drivers would have the opportunity for two full nights prior to
the start of the next work week. For a more detailed discussion
regarding the recovery period provision of this rule, see Section J.8
of this preamble.
F.6. Short-Haul
Motor carrier operations that are conducted solely within a 150
air-mile radius from their terminals and require drivers to return to
their work-reporting location every night are generally considered
short-haul operations. A review of the research literature revealed
only a few studies on short-haul operations. The first study reviewed
was the Massie study [Massie, D.L., et al. (1997)] which found that
short-haul drivers have significantly fewer fatigue related crashes as
compared to drivers for longer trips (0.4 percent for short-haul trucks
compared to 3.0 percent for other trucks). Another important finding
was that ``class 7-8 trucks [26,001 pounds gross vehicle weight rating
(GVWR) and up] have a fatigue-related fatal involvement rate 8 times
higher than class 3-6 trucks [10,001-26,000 pounds GVWR]; over-the-road
trucks have a rate 18 times higher than local service trucks; and the
rate for tractors exceeds the rate for single-unit straight trucks by a
factor of 11'' [Massie, D.L., et al. (1997), p. 35].
A second study evaluated the stress that short-haul drivers face
daily. Researchers that administered a cross-sectional questionnaire to
317 CMV drivers found that short-haul drivers have significantly higher
stress-related symptoms than the general adult population [Orris, P.,
et al. (1997), p. 208]. These drivers perceived their daily events to
be more stressful than the norm because of heavy workloads and
inflexible schedules.
Hanowski, et al. (1998; 2000) conducted two studies on short-haul
drivers--a focus group and a field study. The first study provided a
better definition of what constituted a short-haul driver and the
varied tasks and demands they encounter [Hanowski, R.J., et al. (1998),
p. 1]. The focus groups concluded that driving was not their primary
task, accounting for about 40 percent (less than 5 hours) of their work
time, scattered throughout the day. The two safety problems most often
mentioned by short-haul drivers were dealing with poor driving by
operators of cars, pickups, SUVs, etc., and ``stress due to time
pressure.'' Additionally, Hanowski, et al. [Hanowski, R.J., et al.
(2000), pp. 1-162] conducted a field study of short-haul drivers with
instrumented vehicles to gain a better understanding of critical
incidents that occur within short-haul operations. A critical incident
was defined as a near crash event, i.e., an event that without evasive
action by the driver would likely have resulted in a crash. Of the 249
critical incidents found in the study, 137 were attributed to ``other''
(i.e., non-CMV) drivers, 77 to the short-haul drivers, and 35 were
attributed to incidents outside the control of the driver, such as an
animal in the road. Fatigue played a role in only 6 percent of those
incidents, and no fatigue crashes were reported [Id.].
In determining whether to allow short-haul drivers additional time
to complete their deliveries, the Agency relied on both laboratory and
field research studies which confirm the ability of drivers to work a
16-hour shift without significant degradation of performance. A
laboratory study of 48 healthy adults found the critical wake period
beyond which performance began to lapse was statistically estimated to
be about 16 hours [Van Dongen, H.P.A., et al. (2003), p. 125]. A study
of New Zealand drivers found that drivers could maintain their
performance until about the 17th hour of wakefulness; beyond the 17th
hour, performance capacity was sufficiently impaired to be of concern
for safety [Williamson, A.M., et al. (2000), p. 3].
Some short-haul drivers do accrue fatigue, however, and in a field
study of CMV drivers, it was found that short-haul drivers take short
naps of 1- to 2-hours duration in order to reduce any fatigue accrued
during the course of a normal work day. This study showed that these
drivers take naps within the work shift while they are waiting for
their vehicle to be loaded or unloaded or during normal breaks for
meals [Balkin, T., et al. (2000), p. 4-63]. Short-haul drivers are
unique in that they do not drive for long periods of time. As
mentioned, Hanowski [Hanowski, R.J., et al. (2000), p. 17] found that
only 40 percent of their time is actually spent driving, and that time
was scattered throughout the day. Therefore, traditional performance
models (time-on-task) do not apply because periods of driving are
interrupted during their work day. Based on this evidence, FMCSA has
concluded that because of the uniqueness of short-haul operations, and
because short-haul drivers are involved in fewer crashes than long-haul
drivers, they will be able to maintain alertness and vigilance for an
additional 2 hours for 2 days per week.
The short-haul provision in this final rule takes into account the
available research on short-haul drivers and addresses one of the key
problems confronted by short-haul drivers--the stress of tight
schedules. To set the context, the research discussed in Section F,
``Driver Fatigue,'' and elsewhere in this preamble suggests that driver
fatigue is much less of an issue with short-haul drivers than with
long-haul truckers, primarily because they return home nightly. Many
also have fixed work schedules. Short-haul drivers typically operate
during the daytime hours and are able to sleep at night, which is
generally preferable to sleeping during the day. Short-haul drivers do
not drive for long periods each day, either cumulatively or in a single
session, and driving is usually followed by the physical activity of
unloading throughout the day, which improves alertness. Short-haul
drivers are less likely to fall asleep at the wheel due to driving
monotony. In addition, short-haul driving generally occurs in urban
settings requiring high levels of alertness, but also providing more
stimuli to drivers. Short-haul crashes, when they happen, are more
likely to
[[Page 49996]]
involve property damage than severe injuries or fatalities. Because the
short-haul regime adopted by this final rule increases the work window
available to short-haul drivers, it should relieve them, at little risk
to CMV safety, from the stress and need to hurry caused by inflexible
schedules and limited work hours. The new regulatory regime for short-
haul drivers is described in more detail in Section J.10.
G. Current and Future FMCSA Research
In the 2005 NPRM, the Agency requested information on hours-of-
service research issues, including data gaps and processes, and
methodologies to facilitate data collection and analysis [70 FR 3350].
The Agency received no specific responses to this request. However,
FMCSA continues to proactively research health and safety issues
relevant to HOS.
The FMCSA Research and Technology (R&T) 5-Year Strategic Plan
outlines a vision for delivering an appropriately targeted research and
technology program that will assist in fulfilling FMCSA's primary
mission to reduce crashes, injuries and fatalities involving large
trucks and motorcoaches. One of the challenges identified in the R&T 5-
Year Strategic Plan is to curtail driver fatigue and lack of alertness.
Fatigue and the lack of alertness are factors in CMV crashes, but more
research is needed to better understand the causes of fatigue and
methods of improving alertness. Hours-of-service rules and driver-
oriented programs will need to be continually evaluated and improved.
R&T will investigate, by means of simulator and field studies, the
factors affecting fatigue and the recovery times. Other initiatives
identified in the R&T 5-Year Strategic Plan will also result in the
research and evaluation of driver health issues. Moreover, in an effort
to address the complex HOS health issues confronting CMV drivers, FMCSA
anticipates working with NIOSH on areas of mutual concern and interest.
FMCSA is identifying, through the use of surveys, the best
practices employed by experienced CMV drivers to manage their fatigue.
This study will be published later this year. In addition, FMCSA has
the following fatigue-related studies that are under way in 2005 and
will continue for the next several years.
This research and survey of best practices may contribute to
educational initiatives, to technological aids, to the rulemaking
process on EOBRs, and to other aspects of CMV operation and regulation.
G.1. Fatigue Management Program
The FMCSA Fatigue Management Program (FMP), under development in
partnership with Transport Canada, provides managers and drivers with a
framework for managing driver fatigue through, among other items,
awareness and education on screening for sleep disorders, biocompatible
scheduling practices, and an understanding of the need and implications
of good sleep habits. The program has been developed, pilot tested in
the U.S. and Canada, and is currently in an evaluation phase where its
cost and safety effectiveness will be assessed in an operational
environment. Pending a positive result from the evaluation, the FMP
materials will be revised and finalized, implementation guidelines will
be developed, and comprehensive program materials and guidelines will
be made available to motor carriers and individuals who wish to
implement them.
G.2. Shift Changes and Driver Fatigue Recovery
The FMCSA Shift Changes and Driver Fatigue Recovery Study currently
under way has two primary goals:
<BULLET> Investigate and make recommendations regarding the minimum
duration of off-duty periods required for CMV drivers to recover from
the effects of cumulative fatigue resulting from various work shift
conditions.
<BULLET> Complete a study and publish a report with conclusions and
recommendations from the Shift Changes and Driver Fatigue Recovery
Study.
Hours-of-service initiatives in both the United States and Canada
have highlighted scheduling issues closely related to shift changes, in
particular, the issue of ``weekend'' recovery from cumulative fatigue.
Although CMV drivers may take their ``weekends'' on any day of the
week, the issue of concern is the recovery process that occurs during
these days off. If some degree of sleep deprivation occurs during the
workweek for drivers (especially when that week has involved night
driving and/or shift changes), it is critical that drivers have
sufficient time off during their ``weekend'' to recover full alertness
and physical vitality. This continuing research is focusing on the
recovery process in the context of various schedules including day
driving, night driving, and rotating shifts. After conducting a review
of the relevant literature (Phase I), a research plan was developed
that includes recommended hypotheses to be examined and empirical
research methodologies to be employed (Phase II). In 2005, a contract
was awarded to conduct the empirical studies (Phase III). A final
report stating study conclusions and recommendations (Phase IV) will be
completed by the end of 2007.
G.3. Advanced Driver Fatigue Alerting Technology
The objective of FMCSA's Advanced Driver Fatigue Alerting
Technology research initiative is to increase driver alertness through
a fatigue-alertness monitor. This will be done by establishing a low
cost, reliable, comfortable, rugged, and user-friendly driver fatigue
and alertness technology. Driver fatigue-alerting technology is
intended to monitor driver drowsiness, provide continual alertness
level feedback to the driver, and provide alerts and warnings when the
driver's alertness level falls below a specified threshold.
Currently, FMCSA in partnership with NHTSA is conducting a proof-
of-concept test of a drowsy-driver detection system based on the
PERCLOS (percent of time the eyelids are closed 80% or more over a
given time period) concept. PERCLOS has been demonstrated to be the
most valid measure of driver fatigue. The current infrared-based
technology to measure PERCLOS appears to work well at night, but has
the limitation of not working in daylight, limiting the system's
utility to night driving. FMCSA plans to explore new technologies and
combinations of technologies or measures, such as steering, lane
tracking, etc. that may overcome these limitations, and investigate
development of a more robust system. The objective is to identify and
develop a relatively low-cost device to be used primarily to reinforce
driver fatigue training and promote behavioral change to assure drivers
are well rested.
G.4. Effects of Vehicle Ergonomics on Driver Fatigue
The FMCSA Effects of Vehicle Ergonomics on Driver Fatigue
initiative plans to identify design alternatives to assess the effects
of vehicle ergonomics on driver fatigue. There have been many human
factor studies designed to determine the effects associated with
driving a CMV. However, there are no current studies to determine the
effects of ergonomics on driver fatigue and CMV safety. Therefore, it
is difficult for FMCSA to provide guidance or support to ergonomic-
related rules that could improve safety. This study will review the
project objective, conceive design
[[Page 49997]]
alternatives, examine methods, evaluate feasibility, and develop a
final design incorporating a pilot study capable of demonstrating the
approach's viability.
H. Crash Data
FMCSA compiled and reviewed recent large truck crash data
throughout the industry to assess the impacts of the 2003 rule on crash
rates, and to determine if there are ways to improve the 2003 rule to
better address fatigue and fatigue-related crashes. This review
consisted of examining the following studies and data sources: (1)
Trucks Involved in Fatal Accidents (TIFA), (2) Virginia Tech
Transportation Institute (VTTI) (preliminary), (3) Penn State
University (preliminary), (4) data submitted in comments to the NPRM,
and (5) Fatality Analysis Reporting System (FARS).
H.1. Trucks Involved in Fatal Accidents (TIFA) Data
The Trucks Involved in Fatal Accidents (TIFA) file combines data
from the FARS with additional data on the truck and carrier collected
by the University of Michigan Transportation Research Institute (UMTRI)
in a telephone survey with the truck driver, carrier, or investigating
officer after the fatal crash. TIFA records six variables: fatigue,
time of day, power unit type, carrier type, intended trip distance, and
hours driving since the last 8-hour off-duty period.
The report used by the Agency [Campbell, K.L. (2005)] reviewed TIFA
data for the years 1991 through 2002 (the most recent year available).
The sample size of this file represents over 50,000 medium/heavy trucks
involved in fatal crashes in the U.S., roughly 1,000 of which were
fatigue related. The objective of this report was to identify the
operating conditions where the most fatigue-related crashes occur and
to determine the association of fatigue risk factors with fatal
crashes.
Over the period reviewed, the report found a gradual decline in the
percent of trucks involved in all fatal crashes where truck driver
fatigue was present at the time of the crash, with fluctuations around
the downward trend. Campbell also noted that ``[b]oth prevalence and
risk point to long-haul tractor drivers as the appropriate focus of
efforts to reduce the incidence of fatigue.''
When examining the prevalence of fatigue-related fatal crashes by
the number of hours driven at the time of the crash, the data reveal
that the majority of such crashes occur in the early hours of the trip.
This is largely attributable to exposure, since each trip necessarily
begins with the first hour, which must be the most frequently driven.
However, when examining the relative risk of a fatigue-related crash by
hours of driving, or the number of trucks involved in fatigue-related
fatal crashes in a given driving hour as a percent of all large trucks
involved in fatal crashes in the same hour, the results trend
differently. The likelihood a truck driver was fatigued at the time of
a fatal crash generally increases with the number of hours driven. TIFA
data show that the relative risk of a large truck being involved in a
fatigue-related crash in the 11th hour of driving or later is notably
higher than in the 10th hour of driving.
Despite its scope and complexity, however, TIFA data must be
treated with caution. The number of fatigue-related crashes that
occurred in the 11th hour of driving or later is extremely small. Of
the roughly 1,000 trucks involved in fatigue-related fatal crashes
between 1991 and 2002, only nine were operating in the 11th hour of
driving time.The HOS rule in effect when the TIFA data were collected allowed
only 10 hours of driving, required a minimum off-duty period of only 8
hours, and allowed driving within a 15-hour window that could be
extended by the amount of off-duty time taken during that period. The
2003 rule, which allows up to 11 hours of daily driving but requires 10
hours off duty, may have reduced the risk of driver fatigue and thus
the percent of large truck fatal crashes involving fatigue. The
applicability of TIFA data under the regulatory environment created by
the 2003 rule is no longer clear.
FARS, the source of the crash data for the TIFA study, does not
contain information on driving hours at the time of the crash. TIFA
researchers therefore contact the driver (or the employing carrier)
after the fatal crash to collect such information. However, a good deal
of time can elapse (more than a year in some cases) between the date of
the crash and the date the TIFA researcher first contacts the driver
(or the employing carrier). This delay raises the question whether the
driver can accurately recall his/her driving time so long after the
incident.
H.2. Virginia Tech Transportation Institute Study
FMCSA contracted with the Virginia Tech Transportation Institute
(VTTI) to collect and analyze data on crash risk during the 10th and
11th hour of driving as part of an on-the-road driving study VTTI was
conducting under an FMCSA/NHTSA joint initiative. This study offered an
opportunity to analyze empirical, real-world data obtained under the
2003 HOS rule. The primary goal was to determine the effect of the 11th
hour of driving on driver performance and drowsiness.
Data collection for the study, ``A Field Operational Test of a
Drowsy Driver Warning System,'' began in May 2004. All data collected
through May 1, 2005 were used in this analysis. The researchers have
found no statistically significant difference in the number of
``critical'' incidents in the 10th and 11th hours of driving [Hanowski,
R. J., et al. (2005), p. 9]. The study defines critical incidents as
crashes, near crashes (where a rapid evasive maneuver is needed to
avoid a crash) and crash-relevant conflicts (which require a crash-
avoidance maneuver less severe than a near-crash, but more severe than
normal driving). When the occurrence of critical incidents is used as a
surrogate for driver performance decrements, there is no statistical
difference between the 10th and 11th hour of driving. The study has
also determined that drivers are not measurably drowsier in the 11th
than the 10th hour of driving. These results may be related to another
finding, that drivers appear to be getting more sleep under the 2003
rules than they did when the minimum off-duty period was only 8 hours.
Compared to four sleep studies conducted under the pre-2003 rules (see
section E.1), the Hanowski study found that drivers operating under the
2003 rule are obtaining over 1 hour of additional sleep per day [Id.,
p. 8]
It should be noted, however, that the study is not yet complete.
The study involves 82 drivers working for three trucking companies who
had driven a total of 1.69 million miles as of May 1, 2005, under the
2003 HOS rule. A copy of this VTTI analysis is in the docket.
H.3. Crash Risk and Hours Driving: Interim Report II
In January 2003, the Pennsylvania Transportation Institute at
Pennsylvania State University began work for FMCSA to model the effects
of various commercial driving operational measures (hours driving,
hours of rest, multi-day driving patterns) on crashes [Jovanis, P.P.,
et al. (2005)]. This study collected records of duty status (RODS) for
7-day periods prior to crashes, as well as for a non-crash control
group. The RODS were collected between January 2004 and December 2004.
Through time-dependent logistic regression modeling, the study found a
pattern of increased crash risk associated with hours of driving,
[[Page 49998]]
particularly in the 9th, 10th and 11th hours, and multi-day driving.
The study also suggests a higher crash risk associated with sleeper-
berth operations. For all operations, the study found that the 11th
hour of driving has a crash risk of more than three times that of the
first hour.
Like the VTTI study, this study is incomplete. All RODS were
collected from 3 for-hire motor carriers. The researchers obtained RODS
for 231 7-day periods with one or more crashes and 462 7-day control
periods with no crashes. Driving in the 11th hour occurred only 34
times.
H.4. Comments on Crash Risk and Data
Many companies and associations submitted data on crash and injury
rates. Figure 4 shows changes in DOT recordable accidents, preventable
accidents, and injuries under the 2003 rule, as reported in several
comments. In general, the data show that crash and injury rates were
lower in the year since the 2003 rule went into effect in January 2004.
Figure 4.--Changes in Accident and Injury Rates From 2003 to 2004
[Per million miles]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Commenter Fleet size Crash or injury type 2003 2004 Percent change
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maverick Transportation.............. 1100 power units........ DOT recordable accidents 0.63 0.60 -4.8
Preventable accidents... 0.32 0.24 -25
Crash-related injuries.. .............. .............. -30
Roehl Transport...................... 1600 power units........ DOT accidents involving 0.08765 0.06554 -25
injuries.
ABF Freight System................... 1635 road tractors...... Over-the-road accidents. *1.49 1.42 -4.6
Preventable road *0.715 0.586 -15
accidents.
Injuries for over-the- .............. .............. -41
road drivers.
CR England........................... 2550 power units........ Collision-related .............. .............. -1.9
injuries.
Overnite Transportation.............. 6000 power units........ DOT recordable accidents 0.84 0.80 -4.8
DOT preventable 0.31 0.31 0
accidents.
Collision-related .............. .............. -8.6
injuries.
Werner Enterprises................... 8700 tractors........... DOT recordable accidents 0.6898 0.7092 +2.8
Chargeable accidents.... 0.3311 0.3238 -2.2
J.B. Hunt............................ 11,000 tractors......... DOT recordable accidents .............. .............. -10
DOT preventable .............. .............. -16
accidents.
Driver injuries as a .............. .............. -19
result of motor vehicle
accidents.
Schneider National................... 13,340 tractors......... Preventable major (over .............. .............. -36
$100,000 in cost
accidents.
Fatigue-related major .............. .............. -50
accidents.
Worker's compensation .............. .............. -10
claims from vehicle
accidents.
ATA survey........................... 77,000 to 79,000 trucks. DOT recordable accidents 0.60 0.57 -5.0
DOT preventable 0.24 0.24 0
accidents.
Injuries................ 0.81 0.75 -7.4
FedEx................................ 71,000 motorized At FedEx Express, .............. .............. -3.8
vehicles. fatigue-related
accidents.
At FedEx Ground, DOT .............. .............. -9
recordable accident
rate.
At FedEx Freight, driver .............. .............. -4
injury rate.
National Private Truck Council....... 63 questionnaires....... DOT recordable accidents 0.4921 0.4248 -13.7
Minnesota Trucking Association survey 85 questionnaires (61% Preventable/recordable .............. .............. 61% of members reported no
long-haul carriers). crashes. change. 33% reported a
decrease.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Five-year average. Blank cells indicate data not reported.
In addition to the information provided in Figure 4, eighteen other
companies and associations reported a decrease in crash rates, but did
not provide data to support their claims, and 8 others found little
change in crash rates between 2003 and 2004. The Commercial Vehicle
Safety Alliance (CVSA) cautioned that additional data over a longer
period of time are needed to determine to what extent the 2003 rule has
impacted large truck safety.
ATA reported data showing that carriers had statistically
significant lower average crash rates in 2004, causing ATA to believe
that the 2003 rule is superior to the pre-2003 rule from the
perspective of overall safety. Two State government agencies, however,
pointed out that the FMCSA Motor Carrier Management Information System
(MCMIS) data show an increase in CMV crashes. FMCSA considered the use
of MCMIS data to examine changes in truck-related crashes between 2003
and 2004. However, the Agency decided to utilize FARS data for this
analysis (see below), in lieu of available MCMIS data, for two reasons.
First, the MCMIS crash data do not provide researchers the ability to
isolate fatigue-related crashes, which are critical for this
rulemaking. FARS data do provide this ability. Second, FMCSA crash data
experts believe that, for a variety of reasons, MCMIS currently fails
to capture roughly 20 percent of the fatal crashes that are reported in
FARS. Because of these MCMIS limitations, FMCSA chose to use FARS data
for its analysis.
The information provided by commenters is not available from any
other source, but there is undoubtedly some variability in the methods
and accuracy with which the data were collected. Equally important, the
crash and injury reductions reported by
[[Page 49999]]
commenters cannot be definitively attributed to the effects of the 2003
rule, though some commenters noted that the rule is the only major
variable that changed from 2003 to 2004.
H.5. Fatality Analysis Reporting System (FARS)
FARS is a national census of fatal crashes involving motor
vehicles, including large trucks. FARS data are reported annually by
the States, maintained by NHTSA, and are generally recognized as the
most reliable national motor vehicle crash data available.
FMCSA began by analyzing the 2003 FARS Annual Report File. Because
the 2004 Annual Report File had not yet been released at the time the
analysis for this rulemaking was conducted, FMCSA examined its
predecessor, the ``Early Assessment File,'' which typically contains
most of the fatal crashes that eventually appear in both the Annual
Report and Final FARS data sets. For example, a NHTSA comparison of
calendar years 2002 and 2003 indicates that the Early Assessment File
captured at least 75 percent of the total crashes and fatalities later
included in the Annual Report Files for those years. Since the earlier
months of the calendar year are reported more completely in the Early
Assessment File, FMCSA restricted its analysis to the first 9 months of
2003 and 2004.
FMCSA examined all fatal crashes involving large trucks from
January through September of 2003 and 2004, as well as those where the
truck driver was coded as fatigued at the time of the crash. Results
from this year-to-year comparison are presented in Figure 5.
Figure 5.--Fatal Crashes Involving Large Trucks
[Calendar years 2003 and 2004 (first 9 months of each year)]
----------------------------------------------------------------------------------------------------------------
Fatigue-
related (truck
driver)
Calendar year Total crashes Number crashes
---------------
Percent
----------------------------------------------------------------------------------------------------------------
2003............................................................ 3,120 54 1.7
2004............................................................ 2,954 43 1.5
Year-to-Year Difference (Number)................................ -166 -11 -0.2
Year to-Year % Difference....................................... -5.3 -20.4 -11.8
----------------------------------------------------------------------------------------------------------------
Source(s): 2003 Fatality Analysis Reporting System (FARS) Annual File; 2004 FARS Early Assessment File, National
Highway Traffic Safety Administration.
Figure 5 shows that the total number of fatal crashes involving
large trucks decreased by 166, from 3,120 in 2003 to 2,954 in 2004.
This represents a 5.3 percent reduction. The number of large truck
crashes where the driver was coded as fatigued dropped by 11 crashes,
or 20.4 percent. More importantly, however, fatigue-related fatal
crashes are down from 1.7 percent of all crashes in 2003 to 1.5 percent
in 2004, an 11.8 percent reduction.
These reductions in fatigue-related fatal crashes are very small,
and are not enough to allow final conclusions about the long-term
impact of the 2003 rule on highway safety. However, the available
information may suggest that fatigue-related crashes overall are
trending in the right direction.
H.6. Conclusion
Available information on the effect of allowing 11 hours of driving
time is inconclusive. TIFA is a large data set based on crashes that
occurred across the nation over a relatively extended period. While the
statistical risk increases rather sharply in the 11th hour of driving,
in all the years from 1991 to 2002 TIFA classified only 9 fatal crashes
that occurred in the 11th hour of driving as fatigue-related.
Furthermore, TIFA data were collected at a time when Federal HOS
regulations required only 8 hours off duty, and allowed driving within
an extendable 15-hour window, both of which may have ensured that
drivers operating in the 11th hour were more fatigued than would be the
case under the 2003 rule. Finally, the pre-2003 rule allowed only 10
hours of driving, which means that drivers operating in the 11th hour
were out of compliance with the rules at the time, and therefore may
not be representative of drivers legally operating in the 11th hour
after adoption of the 2003 rule.The on-going studies by the Virginia Tech Transportation Institute
and the Pennsylvania Transportation Institute are being conducted under
the 2003 HOS rule and therefore avoid one of the problems associated
with TIFA data. One finds that the 11th hour of driving poses an
increased crash risk while the other finds no statistical difference
between the 10th and 11th hours of driving. Because of the relatively
short time since the 2003 rule was adopted, both studies acknowledge a
considerable amount of uncertainty which may be resolved once the
datasets increase.
Nearly all of the motor carriers and trucking organizations that
submitted comments to the docket reported lower crash and injury rates
in 2004, when the 2003 HOS rule was first enforced, than in 2003. This
downward trend reveals nothing specific to the 11th hour of driving
time, nor can it be attributed directly to the 2003 rule, but it does
suggest that the net effect of the various provisions of the 2003 rule
has not been harmful. However, the data summarized in Figure 4 were
undoubtedly collected and reported with differing degrees of
statistical sophistication. Still, the number of drivers employed by
the carriers that provided information is very large and the downward
trend in accidents and injuries is unmistakable.
Preliminary FARS data show that there were fewer fatigue-related
fatal CMV crashes in the first nine months of 2004, when drivers and
carriers were subject to the 2003 rule, than in the same months of
2003, when they were subject to the previous rule. Fatigue-related
fatal crashes as a percentage of all CMV fatal crashes were also down
in 2004. This result is similar to the information provided in motor
carrier comments to the NPRM. The downward trend is clear, but the data
do not allow a calculation of crash risk for each additional hour of
driving.
In short, the available crash data do not clearly indicate whether
the 11th hour of driving, combined with the other provisions of the
2003 rule, poses a significant risk. Because the data are not clear,
for the purposes of this rulemaking's RIA, FMCSA conservatively assumed
that the increased fatigue crash risk of driving in the 11th hour could
be explained by the TIFA data as summarized in Campbell 2005, and FMCSA
tests the robustness of the conclusions of this analysis
[[Page 50000]]
through a sensitivity analysis that assumes an even higher relative
fatigue crash risk of driving in the 11th hour.
FMCSA carried out a cost/benefit analysis of a 10- and 11-hour
driving limit and other aspects of this final rule. The results are
described fully in section K.1 and in the Regulatory Impact Analysis
(RIA) filed separately in the docket. Motor carrier operations were
modeled very elaborately. As discussed above, the Agency used a time-
on-task multiplier based on the TIFA data. The model assumed that the
risk of the 11th versus the 10th hour of driving increased, as based on
the TIFA data. FMCSA estimated that a 10-hour driving limit would save
no more than 9.3 lives per year compared to an 11-hour limit, but at an
annualized net cost of $526 million ($586 million in gross costs minus
$60 million in safety benefits), relative to an 11-hour limit. In other
words, a 10-hour driving limit would cost more than $63 million per
life saved.
FMCSA conducted a number of sensitivity analyses regarding the
relationship between fatigue-related crash risk and driving in the 11th
hour to test the sensitivity of the RIA results to the assumptions
built into the model. The sensitivity analyses are contained in Chapter
6, Section 8, of the RIA.
While the Agency did not explicitly estimate the marginal costs and
benefits of limiting daily driving to 8 or 9 hours, FMCSA believes that
such a change would not be any more cost beneficial than a 10-hour
limit. This is due to the fact that, while the increase in the relative
risk of a fatigue-related crash generally rises after the 8th hour of
driving (according to the TIFA data), the increase is more notable in
the 10th hour and later. Therefore, since the Agency's economic
evaluation shows that a 10-hour driving limit results in considerably
higher costs than benefits, compared to an 11-hour limit (holding all
other HOS regulations constant), it logically follows that limiting
driving time to 8 or 9 hours would yield the same result. Additionally,
limiting daily driving to 8 hours, for instance, could increase the
impact of a backward rotating schedule for some drivers (8 hours of
driving + 10 hours off duty = 18 hours) relative to the 2003 rule (11
hours of driving + 10 hours off duty = 21 hours). Such a change has the
potential to increase fatigue-related crash risks due to the disruption
of driver circadian rhythms.
Although FMCSA's mission is improved CMV and highway safety, the
Agency is required by statute to consider the costs and benefits of
requirements it may impose [49 U.S.C. 31136(c)(2)(A) and 31502(d)].
Such consideration is clearly expected to influence the Agency's
rulemaking decisions. The Department of Transportation currently uses
$3 million as the ``value of a statistical life'' (VSL) for rulemaking
purposes. A 10-hour driving limit would essentially have a VSL more
than 21 times the current DOT standard. This cost per life saved is
substantially higher than the maximum $10 million per statistical life
cited by the Office of Management and Budget (OMB) in its guidance to
Federal agencies on conducting regulatory impact analyses [OMB Circular
A-4, p. 30]. Setting the maximum driving time at 10 hours would impose
upon the motor carrier industry, an important sector of the American
economy, regulatory costs entirely disproportionate to regulatory
benefits. Most of the studies and analyses that report an increased
crash risk in the 11th hour of driving are based on data collected
while the driving limit was 10 hours and the minimum off-duty period 8
hours. The agency expected the new 10-hour off-duty period required by
the 2003 rule to reduce driver fatigue and improve safety, despite
allowing 11 hours of driving time instead of 10 hours. Comprehensive
data to test that assumption are not yet available, but many motor
carriers have reported lower crash and injury rates under the 2003
rule, and preliminary FARS data indicates that fatigue-related fatal
truck crashes have declined, both in number and as a percentage of all
fatal CMV crashes. This suggests that the pre-2003 studies and data
connecting the 11th hour of driving with a higher crash risk may no
longer be relevant because the 2003 rule has created better
opportunities for restorative sleep, opportunities which drivers have
used to good effect. In short, it is FMCSA's best judgment that the
$526 million net cost of a 10-hour driving limit is too high to justify
the modest benefits it would generate. This factor, coupled with the
inconclusive nature of available crash data, has led the Agency to set
the maximum allowable driving time at 11 hours after 10 consecutive
hours off duty.
I. Operational Data
To better understand how the motor carrier industry has implemented
the 2003 HOS rule and to help assess the safety and cost impacts, FMCSA
compiled and reviewed several data sets on industry's current use of
the 34-hour recovery provision, the 11th hour of driving, the 14-hour
tour of duty, and split sleeper berth. Additionally, the Agency
examined average weekly hours worked after implementation of the 2003
rule, as well as average nightly sleep. Data compiled or reviewed to
answer these questions included that obtained from the 2005 FMCSA Field
Survey, the 2004 Owner-Operator Independent Drivers Association (OOIDA)
survey, the 2004 Stephen Burks Private Carrier Survey, Schneider
National, Inc. (a large, for-hire truckload carrier), and the Virginia
Tech Transportation Institute study.
I.1. 2005 FMCSA Field Survey
In January 2005, FMCSA initiated a survey by its field staff to
assess the motor carrier industry's implementation and use of the 2003
rule. The data collected were based upon the driver records of duty
status, or time records, as applicable, and included the months of July
2004 through January 2005. The survey results are based upon the
collection of data from a cross-section of industry in 44 States, and
represent a sizeable population of commercial drivers and on-duty
periods in calendar years 2004 and 2005.
The project was conducted in conjunction with normal motor carrier
review activities during the period of January 24, 2005 to February 4,
2005. While the survey was conducted, all compliance and enforcement
decisions and actions followed established Agency procedures. To
enhance the quality of the data collected, the Agency excluded drivers
that were found to have falsified their records.
Overall, 269 motor carriers were surveyed, with 542 driver records
examined. The majority of the survey (81 percent) was completed in
conjunction with a compliance review; with the remaining (19 percent)
in conjunction with a safety audit. A compliance review is an in-depth
review of a motor carrier's compliance with the Federal Motor Carrier
Safety Regulations (49 CFR parts 382 to 399) and Hazardous Materials
Regulations (49 CFR parts 100 to 180), as applicable. Motor carriers
are selected for review based upon safety performance or receipt of a
non-frivolous complaint, or in follow-up to previous compliance/
enforcement actions. A safety audit, on the other hand, is a review of
the carrier's safety-management practices and controls, and is
conducted within the first 18 months of the motor carrier beginning
interstate operations. The safety audit is used to both educate the
carrier and gather data to evaluate and determine whether the carrier
has in place basic safety management controls to ensure safe operation
of CMVs.
Of the carriers surveyed, 85 percent were classified as for-hire
motor
[[Page 50001]]
carriers. Of the drivers surveyed, 80 percent were classified as over-
the-road (OTR) drivers. For the purpose of this survey, OTR was defined
as a driver who did not return to the terminal (work-reporting
location) or home nightly.
The survey found the following:
34-Hour Recovery
Of the 542 drivers included in the survey, 393 (or 72.5 percent)
used the 34 or more hours recovery provision at least once. For these
393 drivers, a total of 1,411 recovery periods were recorded. Looking
at the length of all the recovery periods recorded in the survey
(1,411), 67 percent exceeded 44 hours, 10.8 percent were 36 or fewer
hours, and 4.68 percent were the minimum 34 hours. Slightly less than
27 percent of the drivers had one recovery period of 36 or fewer hours,
while 11.4 percent had one recovery period of the minimum 34 hours.
11th Hour Driving
Of the 6,850 driving periods reviewed, 20.7 percent exceeded 10
hours of driving. This includes 4 percent that reflected driving beyond
the 11th hour. In those cases where daily driving exceeded 11 hours,
either the driver was in violation or not subject to the rule at that
time. Looking just at the driving periods of OTR drivers, FMCSA found
that 22.9 percent of these driving periods exceeded 10 hours of
driving.
14 Hour Tour of Duty
Of the 7,262 tour-of-duty periods reviewed, 15.3 percent exceeded
12 hours, and 4.3 percent exceeded 14 hours. Looking just at OTR driver
tours of duty, FMCSA found that 16.4 percent exceeded 12 hours and 4.6
percent exceeded 14 hours.
Sleeper Berth
Of the 2,928 sleeper-berth periods recorded, 68 percent exceeded 6
hours, and 52.6 percent exceeded 8 hours. A comparison of split-
sleeper-berth periods found that the first period typically had longer
hours (on average 1.5 more hours) recorded than the second split.
Midnight to 6 a.m. (Circadian Trough)
Of the 9,798 records evaluated, a total of 2,776 (28.3 percent) was
found to have recorded duty/driving time between midnight and 6 a.m. In
1,149 of the records (or 11.7 percent) drivers exceeded 3 hours duty/
driving during the midnight to 6 a.m. time period. It should be noted
that 80 percent of drivers included in this survey were classified as
over-the-road drivers (or those that did not return to their work-
reporting location nightly), and as such, night driving may be over-
represented in this sample.
Total Work Hours
On average, drivers recorded 8.78 hours of work per day (driving
and on-duty not-driving), with a standard deviation in average hours
worked per day of 2.9 hours. The daily hours worked produce a 7-day
average of 61.4 hours.
While the drivers included in this survey are not representative of
the entire interstate commercial driver population, this survey does
provide a valuable snapshot of current operations (those under the 2003
rule), as well as the ``real world'' HOS habits of drivers.
I.2. OOIDA Survey
The Owner-Operator Independent Drivers Association (OOIDA)
conducted a web-based survey of its members in 2004 to assess their
experience with the 2003 rule. The survey comprised 17 questions and
addressed such issues as the use of daily driving, the recovery period,
and sleeper-berth provisions, as well as the rule's effect on income,
wait times, time at home, naps, breaks, hours worked, fatigue, and
other factors.
The OOIDA survey asked respondents to provide information on their
type of operation by identifying themselves as either short-haul,
regional, or long-haul drivers. However OOIDA provided no definitions
(i.e., ranges of daily miles driven) for the terms regional, short-,
and long-haul driver. Of the 1,223 OOIDA members who provided such
information in their survey responses, 153 (or 12 percent of
respondents) identified themselves as short-haul drivers with total
weekly miles averaging 2,041 and average runs (or lengths of haul) of
387 miles. According to the definition of short-haul operations used in
the 2003 regulatory impact analysis (RIA), and the definition used in
the RIA for this final rule, short-haul drivers are those with average
lengths of haul of 150 miles or less. As such, the self-identified
``short-haul'' driver respondents to this survey represent what FMCSA
considers to be regional or long-haul drivers, or those with average
lengths of haul greater than 150 miles.
There were 377 respondents to this survey (or 31 percent) who
identified themselves as regional drivers, for whom total weekly miles
averaged 2,369 and average runs equaled 629 miles. Lastly, there were
693 self-identified long-haul drivers (57 percent) in this survey, for
whom total weekly miles averaged 2,709 and average runs equaled 1,196
miles. Additionally, 666 (or almost 55 percent) of the 1,223 survey
respondents indicated that they were leased to a motor carrier, 284 (or
23 percent) operated under their own authority, and the remaining 273
(or 22 percent) identified themselves as company drivers.
Regarding implementation of the 2003 rule, the survey inquired
about OOIDA member use of the 11th hour of daily driving, 34-hour
recovery, and split sleeper berth. Results indicate that during the
month of June 2004 (the period for which information was requested),
all survey respondents as a single group used the 11th hour of driving
an average of 8.4 times, the 34-hour recovery period an average of 3.1
times, and the split-sleeper-berth exception an average of 4.0 times.
To examine these survey results as a percentage of total work periods
available to the driver, we divided survey results by 7- and 30-day
periods, where applicable. For instance, we see that the 11th hour of
driving was used during 28 percent of the 30 days in June (or 8.4
divided by 30). Additionally, the split-sleeper-berth-provision was
used during 13 percent of the total days available (or 4.0 divided by
30). Lastly, the 34-hour recovery was used in 80 percent of the 3.9
available work weeks in June 2004 (or 3.1 divided by 3.9). OOIDA
members who identified themselves as short-haul drivers tended to use
each of these provisions the least. Regional drivers used the 11th hour
of driving and the 34-hour recovery the most on average, and long-haul
drivers used the split sleeper berth the most on average.
With regard to the rule's potential impact on drivers, one survey
question asked, ``Have the new HOS regs helped you to establish and
maintain a 24-hour work/rest cycle?'' 34 percent of driver respondents
felt that the 2003 rule had in fact helped them to establish and
maintain a 24-hour cycle, while 64 percent indicated they experienced
no improvement within the first six months (two percent did not
respond). Among driver types, long-haul drivers revealed the greatest
improvement, with 38 percent indicating that the 2003 rule helped them
establish and maintain a 24-hour cycle, while 30 percent of short-haul
drivers indicated that the 2003 rule helped them to establish and
maintain a 24-hour cycle.
In response to the question, ``Do you get more time at home under
the new HOS regs regime?'' 20 percent felt they did in fact get more
time at home as a result of the 2003 rule, while 77 percent indicated
they experienced no increase
[[Page 50002]]
within the first six months (two percent did not respond). In response
to this question, regional drivers reported the greatest improvement
(22 percent), followed by long-haul drivers (21 percent), and then
short-haul drivers (18 percent).
To the question, ``Do the new HOS regs allow you to get more rest
and therefore reduce your level of fatigue?'' 29 percent of driver
respondents replied the 2003 rule did in fact allow them to get more
rest, while 60 percent indicated no improvement in rest time within the
first six months. Regarding the second part of this question, 14
percent of respondents indicated that they never had fatigue. To this
last question, long-haul drivers indicated the greatest improvement.
Thirty-two percent received more time at home and felt less fatigued
under the 2003 rule. Twenty-three percent of short-haul drivers felt
that they received more time at home and therefore felt less fatigued
under the 2003 rule. Driver responses to the complete set of OOIDA
survey questions can be found in the docket.
I.3. Burks' Private Carrier Survey
Dr. Stephen Burks of the University of Minnesota, Morris, conducted
a survey of private fleets in 2004 to determine the percentage of runs
that utilized the three major provisions of the 2003 rule; namely, the
11th hour of driving, 34-hour recovery, and split sleeper berth.
Additionally, several other operations-related questions were posed. A
total of 31 firms responded to the survey, representing a total of
7,115 power units and 30.3 million miles traveled during the month of
June 2004. The average run for this group of respondents was 537 miles,
with a minimum reported run of 41 miles and a maximum reported run of
2600 miles. A more detailed summary of these survey results is included
in the docket.
Results indicate that the 34-hour recovery period is the provision
most used by private firms responding to this survey. The 34-hour
recovery period was used on average in 61 percent of the respondents'
runs. This does not necessarily mean, however, that all recovery
periods utilized the minimum 34 hours recovery. In fact, as was seen in
the FMCSA Field Survey, many drivers took more than the minimum
required 34 hours off duty. The 11th hour of driving and split sleeper
berth were used less often, according to Burks' survey. The 11th hour
of daily driving was used on average in 31 percent of runs, while the
split sleeper berth was used on 26 percent of runs.
The above percentages are averages, so there is variation among
firms in the use of the provisions. Some private firms indicated they
used each of these provisions on 100 percent of their runs, while
others indicated that they never used them. As a result, when reporting
mean values, any extreme outliers on either side can skew the results.
Thus, the data may be better understood by examining the median value
of responses to each of these questions, or the point at which half of
the survey respondents indicated less use of a particular provision and
half indicated more.
The median for the 34-hour recovery provision was 85 percent,
indicating that half of survey respondents used the provision in fewer
than 85 percent of its runs, while the other half used it in more than
85 percent of its runs (by ``run,'' it is assumed the researchers were
referring to a firm's weekly runs when discussing the 34-hour recovery
provision). Reporting the median value for the 34-hour recovery seems
to validate the relatively high mean value reported earlier (61
percent), in that private firms appear to be utilizing this provision
quite extensively. Regarding the 11th hour of daily driving, the median
was 10 percent, indicating that half the firms surveyed used it in
fewer than 10 percent of runs, while the other half used it in more
than 10 percent. With regard to split sleeper berth, the median value
was 2 percent. Thus, the median values for the 11th hour of daily
driving and split sleeper berth indicate low usage of these provisions,
respectively, by private firms responding to this survey.
I.4. Schneider National
At the Annual Conference of the Transportation Research Board
(TRB), held in January 2005, in Washington, DC, a session was entitled,
``Truck Drivers Hours-of-Service: One Year Later.'' As part of this
session, Mr. Donald Osterberg, a representative from Schneider
National, Inc., one of the largest for-hire trucking companies,
presented information on his company's experience under the 2003 HOS
rule. During this presentation, Mr. Osterberg noted that roughly 10
percent of the Schneider fleet used the 11th hour of daily driving
during the months of June and October 2004. The portion of the
Schneider drivers using a sleeper berth to split their minimum 10-hour
daily off-duty periods was 6 percent in early 2004, falling to roughly
2 percent in June of 2004, and falling further to fewer than 0.5
percent of drivers in October 2004. Also, Mr. Osterberg noted that
between 26 and 32 percent of Schneider drivers used the recovery
provision to take between 34 and 44 hours off between weekly on-duty
periods. These results are consistent with those found in the FMCSA
Field Survey discussed earlier. Mr. Osterberg's statements were
supported by data provided upon request in a handout to FMCSA after the
session. This handout consisted of various summary calculations of
logbook entries pulled for the months of June and October 2004. These
summaries are in the docket.
Regarding commercial drivers' current use of the most important
provisions from the 2003 rule, a summary of responses from the
aforementioned data sources is contained in Figure 6.
Figure 6.--Summary of Survey Information, Carrier/Driver Use of 11th Hour of Daily Driving, 34-Hour Recovery
Period, and Split Sleeper Berth Exemption
----------------------------------------------------------------------------------------------------------------
Percent of runs (daily or weekly) using HOS provision
--------------------------------------------------------
Split sleeper
Date source 11th driving hour 34-hour recovery berth (daily runs
(daily runs or on- (weekly runs or or on-duty
duty periods) on-duty periods) periods)
----------------------------------------------------------------------------------------------------------------
FMCSA Survey........................................... 21 1 73 2 N/P
OOIDA Survey........................................... 28 80 13
Burks Survey........................................... 31 61 26
Schneider National Logbook Summary..................... 1 10 2 N/P 1 .05-6
----------------------------------------------------------------------------------------------------------------
1 Percent of drivers (not daily or weekly on-duty periods).
2 Not provided (NP) because of how the survey data were compiled and/or how they were reported publicly.
[[Page 50003]]
I.5. Virginia Tech Transportation Institute Study
An analysis was conducted of data collected from an ongoing FMCSA-
NHTSA sponsored Field Operational Test of a Drowsy Driver Warning
System. This on-the-road driving study, performed by Virginia Tech
Transportation Institute (VTTI), began collecting data in May 2004. All
data collected through May 1, 2005 were used in the current analysis
[Hanowski, R.J., et al. (2005)]. In all, operational data were
collected and analyzed from 82 CMV drivers working for one of three
licensed trucking companies.
Preliminary results from this study reveal some interesting
patterns concerning sleep duration. The results, based on 1,736 days of
data for 73 drivers, show a mean daily sleep time of 6.28 hours with a
standard deviation of 1.4 hours. Data collected from 80 truck drivers
under the pre-2003 rule and with different driving schedules, found
``drivers averaged 5.18 hours in bed per day and 4.78 hours of
electrophysiologically verified sleep per day over the five-day study
(range, 3.83 hours of sleep . . . to 5.38 hours of sleep)'' [Mitler,
M.M., et al. (1997), p. 755].
The ``hours in bed'' value from Mitler, et al. is a comparable
measure to the mean hours of sleep value resulting from this new study.
A study of long-haul drivers [Dingus, T., et al. (2002), p. 205] found
self-reported sleep per night for single drivers, while on the road, to
be approximately 5.8 hours. This study was conducted under the pre-2003
rule. The VTTI study also used single drivers (i.e., no teams);
consequently, the Dingus et al. study can serve as another reference
point to compare results.
In summary, preliminary results from the VTTI study have found
drivers are sleeping considerably more (up to 1.5 additional hours per
night on average) under the 2003 rule than either the Mitler et al.
study or the Dingus et al. study found under the pre-2003 rule. One
rationale for instituting the 2003 rule was to provide drivers with
additional time off to provide more opportunity to obtain sufficient
sleep. Based on the results of the Virginia Tech Study to-date, drivers
appear to be getting more sleep per night on average, compared to data
collected from drivers under the pre-2003 HOS regulations [Mitler, M.
M., et al. (1997); Dingus, T., et al. (2002)].
J. Comments to Docket and FMCSA Response
Between January 24, 2005, and April 5, 2005, FMCSA received 1,790
comments from approximately 1,590 commenters on the 2005 NPRM. Figure 7
shows the number of comments by type of submitter. The number of
comments, particularly for drivers, is greater than the number of
individual commenters because some submitted multiple documents,
answering in separate submissions each of the questions FMCSA posed.
Figure 7.--Number of Commenters by Type
------------------------------------------------------------------------
Number of
Commenter type comments
------------------------------------------------------------------------
Trucking Associations........................................ 20
Safety Advocacy Groups....................................... 9
Other Associations........................................... 31
Law Enforcement.............................................. 4
Unions....................................................... 3
Carriers..................................................... 223
Drivers: Long Haul........................................... 312
Drivers: Short Haul.......................................... 42
Drivers: Not otherwise specified............................. 1,010
Other Industries............................................. 57
Others....................................................... 79
----------
Total...................................................... 1,790
------------------------------------------------------------------------
Of the carriers submitting comment letters, 203 letters were from
for-hire firms and only 20 from private carriers; 112 identified
themselves as long-haul carriers and 30 as short haul; 71 described
themselves as owner-operators. It is likely that some of those
classified as drivers are owner-operators, but unless they specifically
stated that, they were not classified in that group. The ``Others''
group includes private citizens, a few third-party vendors, and one
academic researcher; most of the private citizens may be drivers, but
did not state that or provide a clear indication that identified them
as drivers.
The following issue sections provide further details regarding
comments submitted to this docket. Although issues are discussed one at
a time, the Agency stresses that the proper focus is on their joint
effects and on the resulting response. Section J.11 discusses the
combination more directly.
J.1. Sleep Loss
In the 2005 NPRM, FMCSA requested information on both the
beneficial and adverse effects of the 2003 rule on the health of CMV
drivers, and expressed particular interest in information about any
increase or reduction in sleep deprivation generated as a consequence
of the 2003 rule. How much sleep do drivers operating under the new
regulations average on a daily basis, the Agency asked, and how has
this average changed as a result of the 2003 HOS rule.
One hundred thirty-four commenters, primarily drivers, responded to
the question. Twenty-nine said that the 2003 rule made no difference to
the amount of sleep they obtained, but 60 said they obtained more sleep
under the new rule.
The Insurance Institute for Highway Safety (IIHS) reported that a
survey it had conducted found that there was a ``slight increase in the
percentage of drivers (from 40 percent in 2003 to 42 percent in 2004)
who said they had driven while sleepy at least once in the past week.''
The percentage of drivers who reported actually dozing at the truck
wheel on at least one occasion in the past month was 13 percent in 2003
and 15 percent in 2004.
FMCSA Response
When asked about the amount of sleep drivers were getting with
regard to the 2003 rule and specifically the 10 consecutive hours off-
duty provision, commenters confirm that drivers are in fact obtaining
more rest today than under the pre-2003 HOS rule. An OOIDA survey
referenced in Section I.2 and a joint NHTSA/FMCSA study referenced in
Section I.5 of this preamble add additional support for this
conclusion.
IIHS' data regarding drivers dozing while driving is not supported
by current crash data; the data suggest that the number of fatigue
crashes have decreased in the first 9 months of 2004 (43 fatigue
crashes) compared to the first 9 months of 2003 (54). Therefore, even
if the IIHS data is accurate and statistically significant, the dozing
behavior does not appear to be relating to an increase in fatigue-
related crashes. It is difficult to comment without knowing all of the
details regarding the IIHS survey. However, based on the Agency's
experience, one would expect that a two percentage point increase in
reported dozing could be a function of sampling error and statistically
insignificant.
J.2. Exposure to Environmental Stressors
FMCSA requested comments on how the 2003 rule, and in particular
the extension of driving time from 10 to 11 hours and the shortened
driving window created by the 14-hour limit, would affect a driver's
exposure to environmental stressors, such as vehicle noise, vibration,
and emissions.
Fifty-nine commenters, including 13 carriers, 44 drivers, one law
enforcement organization, and one private citizen, responded that the
2003 HOS rule had little or no effect on
[[Page 50004]]
exposure to environmental stressors. They stated that modern truck
technology has reduced vibration, noise levels, and emissions and that
the consequences of any additional driving time were either offset by
the workday restriction, or insignificant. ATA commented that potential
driver exposure to diesel exhaust (DE) has decreased to a point below
both Environmental Protection Agency (EPA) and OSHA requirements, and
will probably further improve. ATA included tables illustrating the
improvements. One carrier commented that more stringent regulations,
improvements in technology and road conditions, and better maintenance
practices had reduced environmental stressors.
ATA commented that modern truck cabs are much quieter, far quieter
than the maximum requirement, are well ventilated, and have well
designed, efficient heating and air conditioning units. Physical stress
on drivers, including road vibration, is reduced by power steering.
Many trucks are also equipped with automatic transmissions, further
reducing stress. Improved suspension gives the driver a better ride,
and provides better handling. The comfort and safety improvements in
truck tractors improve the driver's conditions, leading to a reduction
in stress and fatigue; and operators could drive an additional hour,
``yet be safer than drivers in the past.'' Two carriers also commented
that modern trucks have greatly reduced noise and vibration. One
carrier said that due to the lack of vibration, the quality of sleep in
a new truck is ``great,'' while another wrote that drivers become less
fatigued in the improved trucks.
In contrast to the commenters who identified little or no exposure
to environmental stressors, Public Citizen, Advocates for Highway and
Auto Safety (AHAS), and the National Institute for Occupational Safety
and Health (NIOSH) responded with extensive summaries and citations of
current research applicable to the question of exposure to
environmental stressors.
Public Citizen stated that the largest source of diesel emissions
is diesel-powered ``big-rigs,'' and other highway diesel vehicles.
Truck drivers are constantly exposed to DE fumes, ``waiting for a load,
stopping at a truck stop, or operating the truck.'' The long-term
effect of breathing DE and other chemicals poses a significant
potential source of risk for truck drivers, Public Citizen argued,
providing numerous citations of articles and studies relating
particularly to the health impacts of DE. It pointed out that while
FMCSA expected that EPA emissions standards would result in a
significant reduction in emissions from new diesel vehicles beginning
in 2007, current, unmodified, diesel powered trucks would probably be
operating through the 2030s. Public Citizen cited a report recently
released by the Clean Air Task Force (CATF), of which Public Citizen is
a supporting member, highlighting the toxicity of diesel emissions and
numerous acute health risks associated with exposure to diesel
emissions. Public Citizen concluded that ``Diesel particulate matter is
well established as a probable carcinogen. * * * Moreover, fine
particles have been documented by literally thousands of studies as
associated with respiratory and cardiovascular diseases as well as
premature mortality.''
Public Citizen disagreed with FMCSA that the impact of a one-hour
increase in driving hours is unclear. Arguing that the 2003 HOS rule
allowed an increase of more than 600 annual driving hours over the pre-
2003 rule, Public Citizen stated that this increase represented
hundreds of additional hours per year when truckers would be exposed to
elevated levels of DE fumes. They concluded that ``A robust body of
evidence indicates that the exhaust[s] are highly toxic and tied to a
multitude of health risks, and therefore it is negligent of FMCSA to
promulgate an hours of service rule that so significantly increases
drivers' exposure to these fumes.''
AHAS criticized FMCSA for using in the 2005 NPRM almost exclusively
studies that dealt only with commercial drivers, arguing that much
relevant research literature existed in other work-related areas such
as shift work fatigue and performance failures. AHAS provided numerous
citations for studies that it regards as providing directly relevant
findings from other occupational areas. AHAS asserted that FMCSA
ignored relevant research, which it cited, from EPA and others that
conclude that chronic DE inhalation exposure might be a cancer hazard
for humans. AHAS also provided an extensive list of studies in the
field of occupationally related whole-body vibration, and asserted that
FMCSA had not included the most relevant studies in the docket.
AHAS listed and summarized numerous studies addressing the
psychological and physiological effects of long working hours,
irregular shiftwork, and accumulated sleep debt, and provided lists of
sources of statistics and analysis on injuries and illnesses, including
psychological disorders, digestive disturbances, headaches, high blood
pressure, anxiety, gastrointestinal diseases, and reproductive
dysfunction that it considered potentially affecting truck drivers.
NIOSH commented extensively on the issue of driver exposure to
diesel fuel exhaust and other vehicle emissions. NIOSH conceded that
assessing driver exposure to vehicle exhaust is complicated because of
the variety of possible exposure scenarios, including driving, sitting
in the cab, or working at a loading dock. NIOSH noted that few exposure
assessments of commercial drivers had been conducted prior to the 2003
HOS rule and none have been conducted since. NIOSH reported that
current research indicates that some health risks from DE are
associated with particulate matter (PM) in emissions. EPA emissions
standards have led to cleaner burning diesel fuel, and newer engines
produce less PM. NIOSH wrote that DE particles increase allergic
responses, and might lead to harmful structural changes in the airways,
and that there is an association between PM and cardiovascular and
respiratory morbidity and mortality.
FMCSA Response
Most, if not all, of the concerns raised by commenters regarding
driver health have been evaluated and are addressed earlier in this
preamble. FMCSA notes that the majority of commenters, particularly
drivers, stated that the rule will have little or no impact on driver
health. The Agency agrees with ATA's assessment that modern truck
technology has reduced vibration, noise levels, and exposure to DE, and
that the consequences of any additional driving time are either offset
by the workday restriction, or insignificant.
Public Citizen and AHAS cited a number of studies that found an
association between DE and cancer. The TRB driver health team reviewed
these studies and selected studies relevant to this rulemaking to be
summarized for the driver health evaluation discussed earlier in this
preamble. The standards for inclusion were the validity of the
methodology, the relevance of the studied population to truck driving
and the quality of the statistical analysis of health outcomes. FMCSA
has reviewed the research and does not dismiss the association;
however, there have been significant changes in diesel engine design,
changes in emissions standards, and changes in emission types and
composition, which make many of these studies inapplicable to today's
environment. EPA has stated there is considerable uncertainty about
whether ``health hazards identified from previous studies using
emissions from
[[Page 50005]]
older engines can be applied to present-day environmental emissions and
related exposures, as some physical and chemical characteristics of the
emissions from certain sources have changed over time. Available data
are not sufficient to provide definitive answers to this question
because changes in DE composition over time cannot be confidently
quantified, and the relationship between the DE components and the
mode(s) of action for DE toxicity is unclear'' [Ris, C. (2003), p. 33].
Public Citizen commented that the largest source of diesel
emissions is from heavy vehicles. While that is true, DE is only one
contributor to a complex pollution mixture, and there are many other
combustion sources. DE from heavy vehicles represents only 23 percent
of all emissions from all mobile sources. EPA models show that vehicle
emissions from all mobile sources have declined significantly from 1990
to 2005 (average 35 percent reduction in emissions). DE has also
declined 55 percent from 1990 to 2005 and it is projected to decline an
additional 88 percent by 2030. Therefore, drivers are being exposed to
less pollution than they were in the early 1990s when accurate data
first became available.
Further, any health risk associated with DE will continue to
diminish with planned changes in standards for diesel fuel and engines.
EPA projections are based on estimates of vehicle miles traveled and
new vehicles entering and old vehicles leaving the inventory, and
reflect changes in vehicle emissions standards. Reductions in diesel
particulate matter are occurring now; these are not reductions that
will be seen in the next generation of diesel engines. The CATF study
supported by Public Citizen argues that the Federal government needs to
cut DE further and retrofit existing trucks to further reduce DE.
However, as shown the mainstream research community has not
quantitatively determined a precise dose-response relationship between
DE and cancer. In fact, DE at current ambient environmental levels is
not thought to be predictive of cancer; testing on rats at
environmental levels has not led to the development of cancer [Id., p.
35]. EPA has stated ``the DE exposure-response data for humans are
considered too uncertain to derive a confident quantitative estimate of
cancer unit risk, and with the chronic rat inhalation studies not being
predictive for environmental levels of exposure, EPA has not developed
a quantitative estimate of cancer unit risk'' [Id., p. 36].
Additionally, the CATF study is based on some unrealistic and
misleading assumptions. The study suggests that heavy trucks will
remain in the inventory for more than 30 years; therefore changes in
EPA standards will have little effect for many years [Schneider, C. G.,
& Hill, L.B. (2005), p. 8]. FMCSA analysis of commercial vehicle
registration data from Polk & Co., a proprietary data collection firm,
found that fewer than 50 percent of 2004 registered vehicles (Large
Trucks over 26,001 GVWR) were greater than 10 years old and 87 percent
were less than 20 years old. This means that the data being quoted in
the CATF study are from a model that does not appear to be accurate--
the productive life of a CMV is far less than 30 years. Potentially,
this flaw could have dramatic changes in the predications regarding DE.
In addition, comments from Public Citizen, AHAS, and others
regarding the increased health risk due to DE exposure are all
predicated on the assumption that drivers are working more hours as a
result of the 2003 HOS rule. A drastic increase in driving or on-duty
time under that rule is impossible to reconcile with economic reality.
The U.S. economy has been expanding strongly for some time, creating
renewed demand for trucking services and a steady increase in vehicle
miles traveled. But there has been no quantum leap in economic activity
that would demand or support the greatly extended driving hours
asserted by these commenters. Federal Highway Administration data show
that the vehicle miles traveled (VMT) by all trucks increased by 26.03
percent between 1994 and 2002, the last year for which complete
statistics are available. That works out to an average VMT increase of
2.89 percent per year [calculated from <A href="http://frwebgate.access.gpo.gov/cgi-bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.fhwa.dot.gov/policy/ohpi/qftravel.htm">http://frwebgate.access.gpo.gov/cgi-bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.fhwa.dot.gov/policy/ohpi/qftravel.htm</A>
]. The theoretical availability of many more driving and
on-duty hours under the 2003 rule is largely irrelevant. Truckers drive
to meet the demand for transportation, and VMT statistics show that
demand increases (and occasionally decreases) in modest annual
increments. Most of the additional demand is satisfied by adding new
trucks and drivers to the motor carrier industry. The Agency has not
found any data that suggests drivers are actually working significantly
longer hours. Therefore, in the Agency's best judgment, drivers are not
exposed to increased health risk as a result of the 2003 or today's
rule.
J.3. Workplace Injuries and Fatalities
The 2005 NPRM requested comments about the impact of fatigue and
loss of alertness on CMV driver workplace injuries and fatalities, and
any evidence connecting workplace injuries and fatalities to specific
aspects of the 2003 rule or previous HOS regulations. FMCSA explained
that it was interested only in injuries directly related to the HOS
regulations and operating a CMV, not other workplace injuries that are
outside its jurisdiction.
Twenty-eight commenters said that the 2003 rule does not have an
impact on workplace injuries. One carrier, B.R. Williams Trucking,
which had reviewed the company's workplace injuries, stated that there
had been neither an adverse nor a positive change related to the rule.
Work schedules, hours driving, and hours off duty did not affect the
company's injury rate.
Twenty-seven commenters expressed other views about workplace
injuries and fatalities. Nearly all of them agreed that fatigue and
loss of alertness can be a contributing factor, but some commenters
pointed out that the amount of the contribution varies from one
individual to another. One commenter suggested that injury and fatality
statistics should be broken out by type of operation.
Other commenters were uncertain about the impact of the rule. Four
thought the rule gave drivers more rest and limited their hours of
work, so crashes and injuries should be reduced. Six mentioned data
indicating that injuries had decreased in recent years, but they said
those decreases were not necessarily attributable to the 2003 rule.
Four believed the rule's lack of flexibility, the extra hour of driving
allowed, or the inability to stop the 14-hour clock, could contribute
to fatigue and lead to more crashes. Five commenters pointed out that
many drivers' injuries occur when they are loading or unloading and
said that drivers should not be required or allowed to perform these
activities.
Public Citizen asserted the rule has a direct effect on injuries,
and accused the 2005 NPRM of suggesting groundless limitations on
FMCSA's legal responsibility to address them in the rule. For example,
they stated that the ``Workplace Injuries and Fatalities'' section of
the NPRM drew an ``unsupportable'' distinction between injuries
relating directly to the HOS regulations and operating a CMV, and other
workplace injuries and environmental stressors, such as loading and
unloading. Rejecting the Agency's position, Public Citizen cited
several FMCSA reports, technical analyses, and literature reviews that
assessed non-driving issues, including loading and unloading, sleep
apnea, and physical activity and their impacts.
[[Page 50006]]
Many commenters suggested workplace injuries and illnesses have
decreased in 2004. The Motor Freight Carriers Association (MFCA) asked
its membership to provide data and information regarding workplace
injuries. MFCA's preliminary analysis of that data suggests that
injuries and fatalities have decreased in 2004. They commented that
``while we are encouraged by these findings, it would be premature to
attribute the results singularly to the change in hours of service
rules.'' FedEx commented that ``in their pick up and delivery and their
short and long haul divisions combined, there was a 5.44 percent
reduction in injuries even with a 2.2 percent increase in hours worked
for all employees.'' FedEx Freight reports the overall injury and
illness rates for its driver population decreased by almost 4 percent
from 2003 to 2004. Landstar Systems, Inc. commented that it had
experienced 8.6 percent fewer on the job injuries with the 2003 HOS
rule. Maverick Transportation, Inc. commented that it does not track
injuries by loading/unloading, but the total number of injuries
experienced by its drivers in 2004 decreased by 19 percent and crash-
related injuries decreased by 30 percent compared to 2003. J.B. Hunt
commented that it has on-going safety initiatives concurrent with the
hours-of-service changes, so it is difficult to independently conclude
that any changes in injuries are attributable to a single factor. J.B.
Hunt reported that it experienced a 19 percent reduction in injuries
categorized as ``driving/riding'' from 2003 to 2004. The carrier also
found that injuries related to getting in and out of the truck declined
by 18 percent.
FMCSA Response
The Agency agrees with ATA's assertion that the occupational injury
and illness record of the trucking transportation industry has improved
in the last five years. U.S. Bureau of Labor Statistics (BLS) data show
that there have been significant reductions in workplace illness and
injuries in the trucking industry--the number of nonfatal occupational
injuries and illnesses involving days away from work has decreased from
152,803 in 1996 to 129,068 in 2001, a 16 percent decrease. Although the
industrial categories changed slightly in 2003, the number of nonfatal
occupational injuries and illnesses for truck drivers decreased 31
percent between 1996 and 2003.
BLS statistics for 2004 are currently being collected and analyzed
and will not be available until November 2005. For this reason FMCSA
requested data from the public in the 2005 NPRM regarding 2004
workplace injury and illnesses.
Many commenters cited data that showed that workplace injuries and
illness have decreased in 2004. The Agency recognizes these comments
are not a representative sample of the whole industry; however, FMCSA
is encouraged that the information provided suggests that workplace
injuries and illness appear to have decreased from 2003 to 2004. No
commenters have suggested that injuries and illness have increased
solely as a result of the 2003 HOS rule; nor does FMCSA.
Many commenters, particularly drivers, said that they did not see
the connection between the HOS regulation and workplace injuries and
illness. The Agency, based on its experience, however, believes that
there clearly is a connection between driver fatigue and alertness.
Further, one driver responded that ``the loss of alertness or fatigue
affects a truck driver's ability to focus and judge distances causing
crashes. These crashes are less prevalent under the new HOS because a
driver gets more rest under these rules than under the old rules.''
Public Citizen asserted that the NPRM drew an ``unsupportable''
distinction between injuries relating to HOS regulations and other
workplace injuries, which are outside the jurisdiction of the Agency.
``FMCSA expressly distinguishes injuries and fatalities relating to
workplace hazards such as loading and unloading.'' The NPRM stated that
FMCSA did not intend to focus on workplace injuries caused by
conditions beyond the jurisdiction of the Agency [70 FR 3345], e.g.,
falling down a staircase at a motor carrier terminal because a step was
loose. OSHA has the authority to regulate that kind of threat to
workplace safety. Public Citizen seems to assume that fatigue is an
element in many non-driving accidents suffered by drivers, and that the
HOS rule is therefore a ``major contributing factor'' to such mishaps.
FMCSA did not deny that drivers engaged in loading or unloading are
subject to the HOS regulations; the 60- or 70-hour clock continues to
run while drivers handle cargo. The Agency simply directed commenters'
attention to injuries that are immediately related to the HOS
regulations and away from loading or unloading injuries that might be
caused by any number of other factors completely unrelated to HOS, such
as shifting cargo, broken securement straps, inadequate packaging,
incorrectly marked loads, poorly maintained forklifts, or slippery
loading dock surfaces. Public Citizen concluded that ``FMCSA may not
limit its statutory responsibility to driver health for only the period
when a trucker is driving.'' FMCSA has not attempted to confine its
responsibility to driving time. The Motor Carrier Safety Act of 1984,
however, requires only that ``the [Agency's] regulations * * * ensure
that * * * the operation of commercial motor vehicles does not have a
deleterious effect on the physical condition of the operators' [49
U.S.C. 31136(a)(4)]. FMCSA is not, and cannot be, responsible for every
physical infirmity experienced by truck drivers. There are many threats
to health and safety in the modern world, and most of them have nothing
to do with the HOS regulations. The NPRM concentrated on matters the
Agency can address.
J.4. Lifestyle Choices
In the 2005 NPRM, FMCSA noted that lifestyle choices, including
diet and exercise, may impact driver health and safety, but also
concluded that ``Realistically, such choices cannot be regulated by
FMCSA.'' The Agency requested commenters to provide information on the
effect lifestyle choices, such as diet, exercise, and the use of off-
duty time, have on driver safety and health.
Only 36 commenters responded to this request; all appeared to agree
that proper diet and exercise are important elements in maintaining
driver health, but two or three commenters were less certain about the
effect of lifestyle choices on safety. Ten of the commenters insisted
that healthy options are difficult to find on the road, and they were
particularly critical of fast-food meals at truck stops and the lack of
exercise facilities.
Ten commenters argued that lifestyle choices are individual
decisions and cannot be regulated by the HOS rule, except to the extent
the rule provides an opportunity for healthy choices and sufficient
off-duty time. Three commenters approved of the additional off-duty
time provided by the 2003 rule, but others thought the 14-hour
provision made it difficult to maintain a proper diet. One commenter
believed that too much off-duty time had a negative effect. Two
commenters suggested that private-sector training is a more effective
method of helping drivers with lifestyle choices than HOS requirements.
Two other commenters mentioned FMCSA rules that require medical
screening and monitoring for drivers and pointed out that those rules
[[Page 50007]]
already encourage drivers to maintain healthy habits.
Public Citizen, however, alleged the NPRM's ``Lifestyle Choices''
discussion was illegitimate and a disingenuous attempt to narrow
FMCSA's oversight of driver health. In the opinion of this commenter,
the HOS rule had significant potential to influence a driver's diet and
exercise regime, which in turn could greatly influence an individual's
bodyweight, blood pressure, and other health indicators. The commenter
provided no research or data to support this assertion.
With regard to lifestyle choices and their effect on driver
fatigue, Express Inc. commented that its ``experience indicates the
lifestyle decisions made by a driver prior to getting behind the wheel
as well as decisions made while on the road, are by far the most
significant factors in fatigue related accidents.'' Additionally, FedEx
stated that ``lifestyle choices, more than anything else, have the
greatest impact on fatigue related accidents. Without question, the
lifestyle choices drivers make during their off duty time are extremely
significant. Coupled with decisions made on-duty during a trip, they
are the most critical choices relating to fatigue prevention.'' Lastly,
with regard to drivers meeting FMCSA medical requirements, Brink Farms
noted that ``FMCSA can't regulate driver's lifestyle choices, but
regulating their blood pressure levels is regulating driver's health.
Many of our drivers have had to change their lifestyle due to higher
blood pressure than allowed by these limits. Many of our drivers have
begun walking more, and watching their diet more. Exercise alone keeps
a driver healthier and that also keeps them more alert.''
FMCSA Response
The Agency included questions on this issue in the NPRM because
lifestyle choices appear far more likely to directly affect driver
health than many of the occupational and environmental factors faced by
CMV drivers.
Roberts and York (1997) conducted a study for FMCSA entitled
``Design, Development and Evaluation of Driver Wellness Programs.''
They cited a number of areas where drivers make poor lifestyles
choices, for instance by smoking. The percentage of smokers among truck
drivers is nearly double that of the U.S. population. A 1993 study of
2,945 truck drivers reported 54 percent of the respondents smoke
cigarettes or cigars [Roberts, S., & York, J. (1997), p. I-2]. In
contrast, national statistics in 1996 showed that 27.7 percent of all
males and 25 percent of all men and women were smokers [Id.]. The use
of tobacco products is the leading preventable cause of death in the
United States. Smoking substantially increases the risk of
cardiovascular disease, causes about 30 percent of all cancer deaths,
and is the leading cause of chronic lung disease [Id., p. I-1]. Truck
drivers who smoke in their cabs are perhaps at even greater risk of
developing illnesses. They can get a double dose of toxins by inhaling
smoke directly from the cigarette or cigar and by breathing in any
second-hand smoke that remains inside the cab.
A significantly higher percent of CMV drivers were classified as
obese compared to the population in general [Id., p. I-2]. Of 2,945
truck drivers at a trade show, 73 percent were classified as being
either overweight or obese. Of these drivers, 33 percent were
classified as obese (i.e., Body Mass Index Greater than 30) and 40
percent were classified as overweight (i.e., Body Mass Index between 25
and 30) [Id.]. Nationally, only 33 percent of men and women combined
are classified as being overweight [Id., p. I-3]. In the research
literature, obesity is a well-established risk factor for many diseases
such as stroke, cardiovascular disease, hypertension, and diabetes. It
also exacerbates problems with conditions such as arthritis or back
pain. Evidence also suggests that obesity, in conjunction with other
risk factors, places men and women at a higher risk of cancer [Id., p.
I-2].
Roberts and York [Id., p. I-8) identified the prevalence of poor
eating habits among CMV drivers. A 1993 study of 2,945 truck drivers
revealed over 80 percent of these drivers ate only one or two meals per
day and 36 percent had three or more snacks per day [Id., p. I-6].
Furthermore, a 1996 study of 30 drivers in a wellness program revealed
that their favorite meal item while on the road was steak or burgers
and typical snacks were chips, fruit, candy, donuts, and cookies. Only
15 percent of these drivers ate five or more servings of fruits and
vegetables per day, compared to 19.1 percent of all males.
CMV drivers are more likely to be inactive or underactive as
compared to the population in general [Id., p. I-7]. Despite the
importance of regular exercise to disease prevention and health, 50
percent of the truck drivers in a 1993 study never participated in any
type of aerobic exercise and only 8 percent of these drivers
``regularly'' participated in aerobic exercise [Id.]. The 1997 National
Health Interview Survey showed 60 percent of adults do engage in
physical activity for at least 20 minutes per day. Both epidemiological
evidence and medical research demonstrate the ability of physical
activity to reduce the risk of many physiological diseases, including
heart disease, high blood pressure, osteoporosis, diabetes, and breast
and colon cancer, as well as reduce the risk of psychological illnesses
such as depression, anxiety, and stress [Id.].
On three important lifestyle variables, CMV drivers rank well below
average. CMV drivers smoke tobacco at nearly twice the rate of the U.S.
population, have questionable eating habits, and do not exercise
regularly. As a result, twice as many CMV drivers are overweight
compared to the U.S. population. These lifestyle choices are bound to
have profound effects on the health and wellness of CMV drivers, and in
the Agency's best judgment may, by themselves, be predictive of higher
rates of cancer, cardiovascular disease, diabetes, and back problems.
J.5. Driving Time
FMCSA solicited comments in the NPRM on the impacts of incremental
increases in driving time on driver health, the safe operation of CMVs,
and industry economics. In particular, it asked, to what extent did the
increase in maximum driving time from 10 to 11 hours affect health,
safety, and economic factors?
Support for 11-Hour Limit
The majority of commenters (208 out of 360 or 58 percent) who
expressed opinions on the 11-hour driving rule supported it, including
the American Trucking Associations (ATA), the Truckload Carriers
Association (TCA), the Owner-Operator Independent Drivers Association
(OOIDA), and the National Private Truck Council (NPTC).
In all, six trucking associations expressed support for the 11-hour
driving limit. ATA agreed with the 11-hour limit and said that it
should be retained. However, ATA also acknowledged that the
establishment of any driving time limit would benefit from continued
fatigue-related research. TCA stated that the limited scientific data
available did not show a significant distinction between 10- and 11-
hour drive times. NPTC said that the 11-hour limit had improved the
quality of drivers' rest by allowing drivers to make it all the way
home and sleep in their own beds. NPTC said that if FMCSA reverted to a
10-hour limit, the drivers would have to forego returning to home each
evening, or the company would have to schedule additional drivers and
shipments.
The National Industrial Transportation League (NITL) said that
[[Page 50008]]
the additional hour of driving is warranted and justified in light of
the amount of rest that drivers obtain under the 10-hour off-duty
requirement. NITL said that the additional hour of driving time
increases driver and asset productivity, and, in the aggregate, reduces
the need to bring additional trucks onto the roads, which translates
into fewer accidents. The National Armored Car Association (NACA) said
that the 11-hour limit is appropriate and reduces risk to the drivers
of armored cars, who are not allowed to pull off to the side of a road
or stop overnight at a motel as they approach permissible workday
limits, because of the risk of crime. NACA said that the additional
hour provides a margin of safety for responding to such contingencies.
Five other carriers also provided substantive comments supporting
the 11-hour driving limit. The carriers said that the one-hour increase
in the daily driving limit has benefited them economically without
having any detrimental impact on safety. Two of the carriers said their
drivers had benefited from the 11-hour driving limit. ABF Freight said
that some of its drivers who performed defined runs that required close
to ten full hours of driving reported feeling less stress under the 11-
hour driving limit. Crete Carrier Corporation said that its operation
cycles indicated that its drivers' work and sleep patterns had begun to
benefit from the 2003 rule. The carrier said that its drivers appeared
to have adjusted their driving routines to more closely resemble the
traditional workday. The carrier also said that it had teamed with
shippers and consignees to schedule pick-up and delivery times that
were more consistent with drivers' circadian rhythms and to decrease
drivers' non-driving workload and extended detention periods.
A short-haul carrier that hauls loads with special hauling permits
said the 11-hour limit had been especially helpful, because in most
states it could only move loads during daylight hours. The 11-hour
limit allowed drivers to take advantage of the longer daylight in the
summer months to drive additional miles, thus increasing efficiency.
The carrier also said that the extra hour of driving enabled its
drivers to get through metropolitan areas that had a curfew during rush
hour periods. Some of its drivers were now able to deliver one
additional load per week, which increased driver earnings while
improving the company's efficiency.
Opposition to 11-hour Limit
Opposition to the 11-hour daily driving limit came from 152
commenters, including safety advocacy groups, unions, and a minority of
drivers.
Advocacy groups presented the most detailed arguments. IIHS stated
that it did not believe the increase in daily driving time from 10 to
11 hours was supported by scientific evidence. Public Citizen argued
that FMCSA had not presented in the 2005 NPRM any evidence
demonstrating that any changes the Agency would make to the HOS rules
would make the eleventh driving hour safe, much less improve safety, in
accordance with the Agency's statutory mandate. These commenters argued
that FMCSA had failed to demonstrate how a driver's initial restfulness
can ``offset'' the safety risk presented by the additional hour of
consecutive driving.
AHAS said that FMCSA had recognized and documented in its May 2000
proposed rule that the risk of a crash by a commercial driver increases
at a geometric or logarithmic rate as the consecutive hours of driving
increase in each shift. AHAS concluded that by allowing an eleventh
consecutive hour of driving, the Agency has increased the absolute risk
of commercial drivers being involved in fatigued-related crashes.
The International Brotherhood of Teamsters said that any benefits
of the 10-hour rest period and the 14-hour duty-tour were offset by the
one-hour increase in daily driving time and the 34-hour restart
provision. The Transportation Trades Department of the AFL-CIO said
that ``[r]equiring a ten percent increase in driving time as a solution
to driver fatigue makes little sense.''
Some commenters suggested that drivers were being pressured to
drive the entire 11 hours. An attorney with the Truckers Justice
Center, who said that he had represented drivers in proceedings under
the Surface Transportation Assistance Act (STAA) in which the drivers
were disciplined for refusing to drive while impaired due to fatigue,
opposed the 11-hour daily driving limit. He said that the Truckers
Justice Center had spoken with drivers who were concerned about the new
hours of service provision allowing a carrier to force a driver to
drive up to 11 hours in a single tour of duty.
Several commenters presented detailed arguments in favor of a 10-
hour limit. The National Institute of Occupational Safety and Health
(NIOSH) said that its comments submitted to FMCSA in December 2000 were
still valid. Those comments supported a limit of 10 hours of driving
within a 24-hour work/rest cycle of 12 hours on duty and 12 hours of
free time. NIOSH said that this daily cycle would be consistent with
common scheduling practices in other industries that use shifts longer
than 8 hours.
Both Public Citizen and AHAS suggested that drivers should be
allowed to accrue no more than 10 consecutive hours of driving in a
shift. Both added that the research literature and FMCSA itself have
shown that allowing fewer than 10 consecutive hours would result in
even safer operations. Several drivers also supported a 10-hour limit.
Economic Effects of 11-Hour Limit
The Corporate Transportation Coalition (CTC) stated that its few
member companies that engage in long-haul operations believe the 11th
hour of driving has permitted modest productivity gains. Brandt Truck
Line, Inc. stated that the additional hour had improved productivity
(especially in a 50-mph State) by eliminating the need to incur a
sleeper-berth period during the return trip. This allowed the use of
day cab tractors (not sleepers), and a miles per gallon improvement of
15 percent, and a ``gain'' of nearly 20 hours per week in scheduling
continuity, which allows drivers to continue the same scheduled route
each day, rather than changing routes on a day-to-day basis.
ABF Freight stated that in 2004, only 4.6 percent of its dispatches
required the 11-hour rule to complete runs. While this might rise
slightly should the rule become permanent, it was not likely to affect
the majority of its dispatches, due to the fixed nature of its service
center markets. The Overnite Transportation Company stated that the 11-
hour driving rule made its operations cheaper and more efficient,
because it could now haul freight directly, thus using fewer drivers
and fewer tractors and trailers driving fewer miles. The company saves
over $110,000 annually and is able to provide faster transit times.
Georgia-Pacific Corporation stated that productivity is an
appropriate factor for FMCSA to consider because the only other
alternative is to increase the numbers of trucks on the highways, with
accompanying congestion and crashes.
J. B. Hunt said that it randomly selected 80 of its over-the-road
drivers and tracked them for a 30-day period. The carrier found that
the drivers used the 11th hour of driving only 10 percent of the time.
National Ready Mixed Concrete Association (NRMCA), the Massachusetts
Concrete and Aggregate Producers Association, and a carrier
[[Page 50009]]
stated that driving time is generally not a critical issue in the ready
mixed concrete industry. NRMCA cited its 2000 Survey of Ready Mixed
Concrete Truck Driver Activities and Company Operations (Appendix II),
which it said showed that ``concrete delivery professionals'' on
average spend less than half of their time actually driving under the
U.S. DOT definition. Therefore, the 1-hour increase in driving time
contained in the 2003 rule was ``largely inconsequential'' to the ready
mixed concrete industry.
Health and Safety
Commenters generally reported that the increased driving time
either had no impact (57 commenters) or a negative impact (62
commenters) on health or safety.
Advocacy groups saw a clear negative impact. For example, IIHS
cited numerous scientific studies that it said show an increase in
crash risk among drivers operating large trucks for more than 8 to 10
hours. No scientific evidence, IIHS concluded, supports the argument
that the increase in the daily off-duty requirement meant that the 1-
hour increase in driving time would not compromise safety.
Public Citizen argued that numerous studies demonstrate that
increased fatigue and risk are associated with longer consecutive hours
of driving. They claimed that FMCSA's proposed addition of an hour of
driving time would add an hour of exceedingly heightened crash risk,
because the latter hours of driving are the most dangerous. Further,
they asserted that the proposal undermined the Agency's duty to enhance
safety. It cited a 1996 study that found a strong relationship between
single-vehicle truck crashes and the length of consecutive hours spent
driving, with the risk of a crash found to double after 9 hours of
continuous driving. Public Citizen reported another study of truck
driving that found that ``Accident risk increases significantly after
the fourth hour, by approximately 65 percent until the seventh hour,
and approximately 80 percent and 150 percent in the eighth and ninth
hours,'' respectively. They also cited FMCSA's statement in the 2000
NPRM that ``performance begins to degrade after the eighth hour on duty
and that this degradation increases geometrically during the 10th and
11th hours.'' They pointed to a chart in the 2000 NPRM based on data
from the University of Michigan Transportation Research Institute
(UMTRI), Trucks Involved in Fatal Accidents (TIFA) database, which it
said clearly showed a striking rise in the relative risk of a fatigue-
related crash once drivers pass the 9-hour mark. In fact, it asserted
that risk doubles between the tenth and eleventh hours of consecutive
driving. Public Citizen also stated that the 1-hour reduction in on-
duty hours, from 15 hours to 14 hours, is irrelevant in terms of the
number of driving hours. Drivers will tend to gravitate toward the
maximum driving hours possible to enhance their earnings and meet trip
deadlines, they argued, and will minimize non-driving on-duty hours.
In contrast, the California Highway Patrol stated that the
increased risk from the 11th hour of driving would be offset by limits
on the length of the driver's overall work day.
Yellow Roadway Corporation stated that about six percent of
Roadway's single man line-haul operations use the 11-hour clock.
However, it was unable to break out OSHA data for those drivers. The
company did compare OSHA Recordable Injury data of line-haul drivers in
total for the years 2003 and 2004, and said these data show an
improvement of 55 percent from 2003 to 2004. Roadway suggested that
although there may not be a direct correlation to the 11-hour driving
rule, the significant decrease in injury rate for the entire line-haul
operation would suggest that there is no safety or health related need
to change the 11-hour rule.
Alertness Solutions, a scientific consulting firm, submitted a
literature review and technical argument supporting the proposition
that there are very limited data to address a drive-time restriction
and, from a physiological perspective, less foundation to establish how
drive time relates to fatigue. The minimal data available, the
commenter said, do not show significant differences between 10- and 11-
hour drive times. However, Alertness Solutions agreed that a drive-time
limitation could be useful in creating breaks within a duty period, and
breaks have been demonstrated to be an effective strategy to maintain
performance and alertness.
American Moving and Storage Association (AMSA) stated that the
additional hour of driving time has had no adverse effect upon fatigue-
related highway crash experience. The benefits of the existing hours-
of-service rules, however, extend beyond highway safety to driver
acceptance. AMSA reported that one carrier's driver out-of-service rate
declined from 14 percent in 2003 to ten percent in 2004, a 29 percent
improvement. That carrier's number of HOS out-of-service violations
similarly experienced a 29 percent improvement. Another carrier found
the number of its drivers who received false log citations during
roadside inspections decreased 23 percent from 2003 to 2004. AMSA
attributed this to the implementation of the 2003 rule, which more
naturally fit a driver's daily routine and natural circadian cycle.
AMSA also suggested that the 2003 rule is easier for drivers to
understand and easier for dispatchers to work with than the former
hours-of-service regulations. Moreover, the ability to drive for an
additional hour provides operators of household goods moving vans the
flexibility they need to arrive at a destination. Even the relatively
small 1-hour addition to allowable driving time is a tremendous
advantage to the operational efficiency required of all motor vehicle
operations, considering the improvement in comfort, noise penetration,
and maneuverability of commercial motor vehicles today that makes them
less fatiguing to operate than those of even ten years ago. AMSA
concluded that given the one-hour reduction in a driver's overall 14-
hour duty day, the additional hour of driving time was desirable, and
an equitable and balanced complement to a driver's schedule.
OOIDA reported that a survey it had conducted indicated that the
11th hour of available driving time was not always used frequently by
drivers. For the month of June 2004, the average driver used the 11th
hour 8.3 times. According to OOIDA, drivers reported that the
occasional use of this extra driving time had given them the ability to
arrive at a familiar facility where there is room to park their truck,
or to get them home where they have the best opportunity for rest and
restorative sleep. This 11th hour is also used to complete the delivery
of a load, taking the pressure off the driver to deliver the next day.
OOIDA reported that drivers said they do not believe that the extra
hour of driving impaired their safe operation of a CMV, and that it
often put them in a position to obtain better rest or sleep. They would
like to retain this flexibility.
FedEx Corporation reported that FedEx Freight has no drivers who
were consistently logging 11 hours of driving. FedEx Freight has no
regular runs that require a driving time of 11 hours. Only about 2
percent of bid runs had a driving time of between 10 and 10.5 hours. No
crashes had occurred after the 10th hour of driving.
Several drivers suggested that the 11-hour driving period should be
limited by other requirements, or they suggested other limits.
FMCSA Response
Because of the importance of driving time to this rule and the
conflicting
[[Page 50010]]
views of the commenters, FMCSA examined a wide range of research
literature and statistical data and performed a careful cost/benefit
analysis of two alternative driving limits: 10 hours and 11 hours. The
agency has decided to adopt a driving-time limit of 11 hours within a
14-hour window following 10 consecutive hours off duty.
Crash Data
Although FMCSA's analysis of the available crash data is presented
in detail in section H, some of the information bears repeating here.
Trucks Involved in Fatal Accidents (TIFA) Data
The TIFA file combines data on fatal crashes from FARS with
additional data collected by UMTRI, including the number of hours
driven since the last 8-hour off-duty period at the time of the crash.
Campbell [Campbell, K.L. (2005)] reviewed TIFA data for the years
1991 through 2002 to identify the operating conditions where the most
fatigue-related crashes occur and to determine the association of
fatigue risk factors with fatal crashes. He found that the majority of
fatigue-related crashes occur in the early hours of the trip. This is a
function of exposure, since all drivers drive in the first hour, while
fewer drive in later hours, i.e., the early hours of trips are the most
frequently driven. However, when examining the relative risk of a
fatigue-related crash by hours of driving, the results are different.
The likelihood a truck driver was fatigued at the time of a fatal crash
generally increases with the number of hours driven. TIFA data show
that the relative risk of a large truck being involved in a fatigue-
related crash in the 11th hour of driving or later is substantially
higher than in the 10th hour of driving.
TIFA data are not necessarily applicable to this rulemaking,
however. Only 9 fatigue-related fatal crashes where the driver was
operating in the 11th hour were recorded between 1991 and 2002. The
statistical significance of such a small number is questionable. TIFA
data were collected when the minimum off-duty period was only 8 hours
and the driving limit 10 hours. The current 10-hour off-duty
requirement means drivers have so much more opportunity for restorative
sleep that the relative risk of the 11th hour of driving revealed by
TIFA may no longer be relevant. Finally, UMTRI conducts interviews with
drivers or carriers to supplement the FARS data, but may do so as much
as a year after a crash. It is unclear whether drivers can accurately
recall the number of hours they had driven that long after the event.
Virginia Tech Transportation Institute Study
The Virginia Tech Transportation Institute (VTTI) is currently
conducting a real-world, empirical study of crash risk during the 10th
and 11th hour of driving.
The researchers have found no statistically significant difference
in the number of ``critical'' incidents in the 10th and 11th hours of
driving [Hanowski, R.J., et al. (2005), p. 9]. The study has also
determined that drivers are not measurably drowsier in the 11th than
the 10th hour of driving. These results may be related to another
finding, that drivers appear to be getting more sleep under the 2003
rules than they did when the minimum off-duty period was only 8 hours.
Compared to four sleep studies conducted under the pre-2003 rules,
Hanowski and his colleagues found that drivers operating under the 2003
rule are averaging over 1 hour of additional sleep per day [Id., p. 8].
Crash Risk and Hours Driving: Interim Report II
The Pennsylvania Transportation Institute at Pennsylvania State
University is currently modeling the effect on crashes of hours of
driving, hours of rest, multi-day driving patterns and other factors
under the 2003 rule [Jovanis, P.P., et al. (2005)]. This study
collected records of duty status (RODS) for 7-day periods prior to
crashes, as well as for a non-crash control group. The study found an
increased crash risk associated with hours of driving, particularly in
the 9th, 10th and 11th hours, and multi-day driving.
Comments on Crash Risk and Data
Many companies and associations submitted data on crash and injury
rates. In general, their data show that crash and injury rates were
lower in the year since the 2003 rule went into effect in January 2004.
ATA reported data showing that carriers had statistically
significant lower average crash rates in 2004, causing ATA to believe
that the 2003 rule is superior to the pre-2003 rule from the
perspective of overall safety.
The information provided by commenters is not available from other
sources, but there is certainly some variability in the methods and
accuracy with which the data were collected. In addition, the lower
crash and injury rates cannot be definitively attributed to the effects
of the 2003 rule, though some commenters noted that the rule is the
only major variable that changed from 2003 to 2004. Finally, the data
do not reveal anything about the relative risk of the 10th or 11th hour
of driving.
Fatality Analysis Reporting System (FARS)
FARS is generally recognized as the most reliable national database
on fatal motor vehicle crashes. FMCSA compared the first 9 months of
FARS crash data from the 2003 Annual Report with the first 9 months
from the 2004 Early Assessment File (the difference is explained in
Section H).
The total number of fatal crashes involving large trucks decreased
from 3,120 in 2003 to 2,954 in 2004, a 5.3 percent reduction. The
number of large truck crashes where the driver was coded as fatigued
dropped as well. More important than either of these figures, however,
are the data showing that fatigue-related fatal crashes are down from
1.7 percent of all crashes in 2003 to 1.5 percent in 2004, an 11.8
percent reduction.
Although the data are still preliminary, all FARS measures of
fatigue-related crashes are trending downward. The data, of course, do
not allow any firm conclusion about the extent to which the 2003 rule
may have contributed to that result.
Operational Data
FMCSA gathered operational data during compliance reviews and
safety audits to determine how the various provisions of the 2003 rule
are being employed by the motor carrier industry. The Agency also
reviewed other survey material and comments to the docket on this
subject. Available data indicate that driving into the 11th hour is far
from universal, with utilization rates ranging from 10 to 28 percent.
FMCSA's own survey of driver records found that only 20.7 percent of
the recorded driving periods exceeded 10 hours. There is no reason to
believe that a full 11 hours of driving will ever become the standard
for the industry. Drivers need to deal with operational,
administrative, and personal matters which typically reduce driving
time well below the maximum allowable hours.
As stated above, numerous carriers support the 11th hour of driving
since it allows drivers to return home within a day so they can sleep
in their own beds. FMCSA also notes that the provision has increased
industry productivity through increased flexibility without impacting
safety based on available data, specifically crash rates (see Crash
Data discussion, above). A number of commenters said that, since trip
lengths have not changed
[[Page 50011]]
as a result of the 2003 rule, the 11th hour serves primarily to reduce
the stress of trying to complete a run by the end of the 10th hour.
With an extra hour of driving time, drivers are able to relax a bit and
perhaps drive less aggressively.
As noted in the comments, use of the 11th hour is also justified
due to improvements in truck comfort, noise penetration, and
maneuverability, which have decreased trucker fatigue over the past
decade.
Research and Literature Review
The scientific literature on fatigue and performance factors
includes notably different, and indeed inconsistent, results. The
Agency found that the research on driving time is limited and the
conclusions mixed. A fatigued driver is prone to perform less
effectively on tasks requiring vigilance and decision-making than a
person who is alert. Fatigue is associated with a higher degree of
crash risk. In practice, however, it is difficult to establish the
precise effect a given driving or on-duty period will have on fatigue,
alertness, or driver performance. Modest differences in study designs
may produce surprisingly different results.
Research on the effects of driving time falls into three
categories: (1) Operational studies of on-road working environments,
(2) laboratory studies under controlled conditions, sometimes using
driving simulators, and (3) analysis of crash or performance data. The
results are far from uniform.
Operational and laboratory studies have generally found little or
no statistically significant difference in driver drowsiness or
performance between the 10th and 11th hours of driving [O'Neill, T.R.,
et al. (1999), p. 48; Wylie, C.D., et al. (1996), pp. 5.13-5.14;
Hanowski, R.J., et al. (2005), p. 9]. These findings are contradicted
by other research involving drivers operating under the pre-2003 HOS
rule. A frequently-cited 1978 study found evidence of fatigue, measured
both subjectively and objectively, in less than the 10 hours of driving
then allowed by the HOS rules [Mackie, R.R., & Miller, J.C. (1978), pp.
219-221]. This study, however, required a driver to take only 8
consecutive hours off-duty, which probably limited the hours actually
available for sleep (as discussed later in section J.7). The 2003 rule
and today's final rule provide drivers an additional 2 hours off duty,
creating a much improved opportunity for 7 to 8 hours of sleep per day.
Research analyzing crash and performance data usually focuses on
police reports and driver records of duty status (RODS) to establish
crash-risk factors, like the time of day the crash occurred, the number
of hours driven since the last off-duty period, the number of hours
since the last sleep period, and the length of the last sleep period.
As mentioned above, these studies typically find that the risk of a
fatigue-related crash increases with the number of hours driven, and
particularly after the 10th hour. On the other hand, sample sizes for
the 11th hour of driving, and beyond, are very small, and data
collection procedures for TIFA are less than optimal.
The evaluation of some research, particularly in the operational
category, is complicated by the variations in study design and data
collection.
A 1996 operational study of 80 long-haul drivers engaged in
revenue-generating runs in the U.S. (under the 10-hour driving limit)
and Canada (under that country's 13-hour driving limit) reported that
time-on-task was not a strong or consistent predictor of observed
fatigue. This study found no difference in drowsiness, as observed in
video records of comparable daytime segments, between 10 and 13 hours
of driving. Some measures, such as lane tracking, individual cognitive
performance, and self-rating of fatigue were better at 10 hours of
driving than at 13 (lane tracking was confounded by differences in
driving routes and road conditions in the two countries). Conversely,
reaction time was better at 13 hours of driving than at 10. The authors
noted that the lack of variance in drowsiness between the driving
periods may be attributable to the fact that the study measured only
daytime drowsiness. Other research suggests the body's circadian rhythm
limits the negative effects of longer hours during daytime operations
[Wylie, C.D., et al. (1996), pp. 5.13-5.14].
A 1999 study evaluated the effects on fatigue and performance
during a daytime schedule of 14 hours on duty and 10 hours off duty,
with drivers performing simulated driving and loading/unloading tasks.
The authors found mild cumulative effects on subjective measurements of
sleepiness; a slight but statistically significant deterioration in
duty-day subjective sleepiness, reaction time response, and measures of
driving performance over the course of a week; but no cumulative
deterioration of driver response in crash-likely situations. The
authors reported that a schedule of 14 hours on duty (with 12 hours of
driving) and 10 hours off duty for 5 consecutive day periods did not
appear to produce significant cumulative fatigue over the 2-week
testing period [O'Neill, T.R., et al. (1999), p. 48].
Breaks, Naps and Driver Fatigue
The Agency considered a mandatory rest period (break) to mitigate
any possible fatigue related to the 11th hour of driving. Scientific
research suggests that rest breaks, including naps, while not reducing
accumulated fatigue, refresh drivers and enhance their level of
performance and alertness on a short-term basis [Belenky, G. L., et al.
(1987), p. 1-13 ; Wylie, D. (1998), p. 13]. The Agency concluded that
such a break would be difficult for State and Federal enforcement
personnel to verify and would significantly interfere with the
operational flexibility motor carriers and drivers need to manage their
schedules.
Still, FMCSA encourages carriers to establish a break or napping
policy as part of an overall fatigue management program. Several
studies have shown that a nap during a night shift can lessen the
fatigue felt overnight [Matsumoto, K., & Harada, M. (1994), p. 899;
Rogers, A.S., et al. (1989), pp. 1202-1203]. A study found that a 20-
minute ``maintenance'' nap helped to improve daytime self-rated
sleepiness and performance levels on a variety of tasks, including
logical reasoning, mathematical calculations, and auditory vigilance
[Hayashi, M., et al. (1999), p. 272]. Research suggests that a short
nap of 10 to 20 minutes (but generally for less than 45 minutes) can
provide a beneficial boost in driver alertness.
Driver Health Impact
The issue of CMV driver health is complex, and involves many
external factors (lifestyle, diet, and other personal behavior/choices)
that are beyond the scope of the HOS rules. As discussed above (Section
E--Driver Health), FMCSA found little research on a possible
relationship between HOS regulations and driver health. Longer driving
time increases driver exposure to diesel exhaust and chemicals, noise,
and vibration, but dose/response curves clarifying the effect of such
exposure do not exist. Therefore, in the Agency's best judgment, the
difference between a driving limit of 10 and 11 hours is
inconsequential from the standpoint of driver health.
Conclusion
Available information on the effect of allowing 11 hours of driving
time is inconclusive. TIFA classified only 9 fatal crashes that
occurred in the 11th hour of driving as fatigue-related between 1991
and 2002. Whatever the statistical risk of driving in the 11th
[[Page 50012]]
hour, FMCSA cannot make a reasonable choice between a 10- and an 11-
hour driving limit on the basis of only 9 fatal crashes over a 12-year
period.
The on-going studies by the Virginia Tech Transportation Institute
and the Pennsylvania Transportation Institute seem to have reached
completely incompatible conclusions. The latter finds that the 11th
hour of driving poses a significant crash risk while the former detects
no statistical difference between the 10th and 11th hours of driving.
The different methods used by both research teams appear to be valid.
Trucking industry comments to the docket generally reported lower
crash and injury rates in 2004 than in 2003. This reveals nothing about
the 11-hour driving limit or the 34-hour restart provision, nor can the
improvements be clearly linked to the 2003 rule, but it certainly
implies that the 2003 rule has not harmed highway safety.
Preliminary FARS data show that fatigue-related fatal crashes as a
percentage of all CMV fatal crashes were down in the first nine months
of 2004 compared to the same period in 2003. This is consistent with
the information provided in motor carrier comments to the NPRM. The
data do not allow a calculation of crash risk for each additional hour
of driving. It is also possible, however unlikely, that the FARS Early
Assessment File for 2004 does not accurately reflect the data in the
2004 Annual Report, which was not available when FMCSA conducted its
analysis.
In summary, the available crash data do not clearly indicate
whether the 11th hour of driving, combined with 10 hours of off-duty
time, poses a significant risk.
An 11-hour driving limit is favored by most motor carriers and
drivers, and is economically beneficial to some carriers. On the other
hand, it provides no real advantage over a 10-hour limit for many
short-haul carriers. Advocacy groups and some drivers prefer shorter
driving times, though there is no consensus on what the shorter limit
should be. Use of the 11th driving hour varies widely among motor
carriers and individual drivers, but all available data show
utilization rates far below 50 percent. The research literature on
driver health is not sufficiently detailed to differentiate between any
possible effects of a 10- and an 11-hour driving limit. Like the crash
research and data, the comments and operational data do not point
unambiguously toward a single conclusion.
FMCSA carried out a cost/benefit analysis of a 10- and 11-hour
driving limit and other aspects of this final rule, as reported in
section K.1 and the stand-alone Regulatory Impact Analysis (RIA) filed
in the docket. Motor carrier operations were modeled in detail. The
Agency used a time-on-task multiplier which assumed that the crash risk
from the 10th to the 11th hour of driving increased based on the TIFA
data. The analysis demonstrated that a 10-hour driving limit would save
no more than 9.3 lives per year compared to an 11-hour limit. The
annual net cost of a 10-hour limit, however, compared to an 11-hour
limit, would be $526 million ($586 million in gross costs minus $60
million in safety benefits). A 10-hour driving limit would cost more
than $63 million per life saved.
While the Agency did not explicitly estimate the marginal costs and
benefits of limiting daily driving to 8 or 9 hours, FMCSA believes that
such changes would be even less cost beneficial than a 10-hour driving
limit and would allow a driving/rest cycle less consistent with driver
circadian rhythms than an 11-hour limit. See section H for further
discussion of this issue.
FMCSA is required by statute both to improve motor carrier and
driver safety and to consider the costs and benefits of its
requirements [49 U.S.C. 31136(c)(2)(A) and 31502(d)]. The Department of
Transportation currently uses $3 million as the ``value of a
statistical life'' (VSL) for rulemaking purposes. Because a 10-hour
driving limit would cost $63 million per life saved, compared to an 11-
hour limit, the VSL for the lower limit would be 21 times the DOT
standard. A $63 million VSL is over six times higher than the maximum
VSL cited by the Office of Management and Budget (OMB) in its guidance
to Federal agencies on conducting regulatory impact analyses, i.e., $10
million [OMB Circular A-4, p. 30]. The Agency cannot impose regulatory
costs so far in excess of regulatory benefits. FMCSA expected the new
10-hour off-duty period required by the 2003 rule to reduce driver
fatigue and improve safety, despite allowing 11 hours of driving time
instead of 10 hours. Many, though not all, motor carriers have reported
lower crash and injury rates under the 2003 rule, and preliminary FARS
data show that fatigue-related fatal truck crashes have declined as a
percentage of all fatal CMV accidents. This suggests that the pre-2003
studies and data showing a sharply increased crash risk in the 11th
hour of driving may no longer be relevant because drivers have used the
10 off-duty hours required by the 2003 to reduce fatigue. It is thus
FMCSA's judgment that the $526 million net cost of a 10-hour driving
limit is too high to justify the potential benefits it would generate.
Today's final rule therefore sets the maximum allowable driving time at
11 hours after 10 consecutive hours off duty.
J.6. Duty Tour
In the 2005 NPRM, FMCSA requested comments on the impacts of the
2003 rule decrease in the duty period for drivers from 15 non-
consecutive hours to a non-extendable 14 consecutive hours.
Impacts on Safety and Health
Almost 600 drivers and about 100 carriers, as well as OOIDA, the
National Association of Small Trucking Companies, CTC, and NPTC, urged
that breaks, meals, and time spent loading and unloading be exempted
from the 14-hour duty tour. A substantial majority of commenters,
mostly drivers and owner/operators, opposed the change from 15
cumulative hours to 14 consecutive hours of on-duty time. Drivers, in
particular, stated that the consecutive duty time requirement caused
them to skip meals or naps when they were needed, and generally
increased stress that leads to speeding and more aggressive driving.
Several commenters believed the opportunity to work 14 consecutive
hours compromised safety and favored a return to the previous
requirement of 15 cumulative duty hours. Most of the commenters cited
the need for meal breaks and other breaks for rest and exercise to be
``off the clock,'' so drivers are not penalized for taking time to eat
a meal or nap when they feel fatigued. Several trucking associations
cited fatigue as the primary impact of the consecutive 14-hour rule.
Because, they claim, drivers are discouraged from taking breaks to rest
or have a meal, they drive straight through causing fatigue and stress.
Two associations noted that the consecutive 14-hour rule has the
unintended consequence of increasing the number of driver layovers,
meaning that drivers more frequently sleep away from home, even though
studies cited by FMCSA suggest that drivers who return home every day
experience fewer fatigue-related, serious crashes than those who sleep
while on the road. Many commenters urged FMCSA to revise the HOS rules
to allow a driver to extend the 14-hour window by up to two hours by
taking off-duty rest breaks throughout the day as needed. The Minnesota
Trucking Association (MTA) reported that 51 percent of its drivers took
naps to supplement sleep or maintain alertness. However, of the 49
percent who did not nap, 42 percent
[[Page 50013]]
said that the 14-hour consecutive duty rule discouraged naps.
The 131 commenters who approved the change to 14 consecutive duty
hours made a variety of arguments in its favor. Several commenters
believed the change was a positive one because it prevents shippers,
receivers, and companies from abusing the off-duty hours and forcing
drivers to use them as unpaid time. The National Industrial
Transportation League (NITL) commented that 2003 rule ``supports driver
productivity because the 14-hour window allows drivers ample time to
perform such tasks as loading, unloading, fueling, vehicle inspection,
and completion of paperwork that are part of a typical day.'' Advocates
for Highway and Auto Safety stated that a return to a cumulative
measure of duty time would restore the abusive practices that prevailed
with the previous HOS rules, including the ability of shippers and
receivers to intimidate drivers to wait in line for loads, load and
unload their freight, and exceed maximum driving hours by concealing
these actions as ``off the clock'' rest or meal breaks. Several
commenters also noted that the consecutive hours requirement would
promote safety by keeping drivers on a 24-hour circadian schedule.
Economic Impacts
Several carriers noted that the 14-hour rule had increased their
productivity and made their fleets more efficient. One carrier stated
that the rule allowed it to pressure customers to speed up loading and
unloading. In concert with a positive economic environment, this
allowed a rate increase. Another carrier noted that the consecutive 14-
hour rule made it easier for a company to audit and manage driver
hours, and that the rules were easier for drivers to understand and log
their time accurately. The general consensus among drivers was that
their workday, on average, is shorter under the new rules. They no
longer work 20-hour days due to the 14-hour consecutive requirement.
One driver stated that this is because shippers and receivers are more
aware of the time restrictions that drivers face and do not delay
drivers as long as they did in the past.
The NITL commented that shippers have made significant changes. For
example, ``operations at loading docks have been reconfigured to
decrease dwell time and to expedite loading and unloading in order to
minimize driver on-duty time not devoted to driving, and to maximize
driving time with the new 14 consecutive hour rule.'' The changes were
necessary given the ``new'' value associated with a driver's time. They
too suggest that shipper and motor carrier operations have become more
efficient in response to the 14-hour duty tour rule.
Several other carriers, however, stated that the consecutive 14-
hour rule had caused a loss of productivity and fleet utilization,
while increasing costs, thereby reducing profits. Some commenters noted
that the inflexibility of the consecutive 14-hour rule
disproportionately affects small businesses, many of which are forced
to hire additional drivers to accommodate irregular delivery schedules.
A few of these commenters also cited public safety concerns associated
with the lack of flexibility. For example, the National Propane Gas
Association stated that nearly 60 percent of its members are
experiencing difficulty in handling emergency or after-hours calls
requiring an immediate response. Short-haul drivers also stated that
the 14-hour rule had increased costs and reduced productivity and
driver earnings. The American Bakers Association surveyed its members
and estimated the cumulative cost increase to its companies'
distribution systems to be between 12 and 15 percent. Several
commenters noted that the impacts to short-haul drivers are more
significant than those imposed on long-haul drivers. Four commenters
cited FMCSA's admission that, while the benefits of the new HOS rules
accrue mostly to long-haul drivers, the cost burden falls largely on
short-haul operators.
Two carriers stated that the consecutive 14-hour rule imposes an
economic penalty on long-haul drivers who wish to take a rest break and
decreases their earning potential by not allowing the 14 hours to be
extended.
FMCSA Response
Under the pre-2003 HOS rule, a driver could extend the 15-hour on-
duty period by taking breaks during the day. Thus, the pre-2003 rule
permitted an operator to drive after having been at work over 15 hours.
The Agency ended this in the 2003 rule, by prohibiting drivers from
extending their on-duty period with ``off-duty'' breaks. The 2003 rule
prohibited driving after the 14th consecutive hour of beginning work or
coming on-duty. This created a non-extendable period within which the
driver could drive up to 11 hours and effectively ended the allowance
of breaks to extend daily duty tours. The Agency's research found time
spent working (and not simply time spent driving) contributes to a
driver's fatigue and thereby impacts performance in long-haul
operations [Williamson, A.M., et al. (1996), pp. 713-717; Williamson,
A.M., et al. (2000), pp. 43-44; Van Dongen, H.P.A., et al. (2003), p.
125].
In developing this final rule, the Agency considered whether the
scientific research, studies, data, and comments justified adopting a
14-hour driving window, or required some other provision. As noted
earlier, a number of commenters, drivers in particular, reported that
the consecutive duty time requirement causes them to skip meals or naps
when they are needed, and generally increases stress and leads to
speeding and more aggressive driving. After a thorough evaluation of
the data and comments, FMCSA has decided to allow drivers to drive up
to 11 hours within a 14-hour window after coming on duty.
Crash Data
The crash data reviewed by the Agency in developing this rule is
discussed earlier in Section H. Several motor carriers and associations
submitted data with their comments reflecting a decrease in crash and
injury rates in 2004 compared with 2003. The data suggest a positive
improvement in safety performance. It is impossible to definitively
link a specific provision of the 2003 rule with the improved safety
performance during 2004; however, the research and crash analysis show
longer continuous work hours can increase the risk of a fatigue-related
crash, as discussed later in this section. Further analysis suggests
that the crash-impact of longer work hours is more specifically
associated with large CMVs (greater than 26,000 pounds). Analysis of
1994-2002 crash data found that these CMVs account for 87.3 percent of
all fatigue-related fatal crashes [Campbell, K.L. (2005)].
Operational Data
Based on the recent FMCSA survey [See Section I, FMCSA Field Survey
Report (2005)] of 7,262 tour-of-duty periods, the Agency found that
15.3 percent exceeded 12 hours and 9.2 percent exceeded 13 hours.
Looking at over-the-road (OTR) driver tours of duty, 16.4 percent
exceeded 12 hours and 9.4 percent exceeded 13 hours. These data show
that the vast majority of drivers are not using the full 14-consecutive
hour duty tour. The data suggest that drivers represented in the survey
have time available within the current 14-hour duty tour to take
breaks. The survey findings are based upon the review of 269 motor
carriers, of which 85.9 percent (231) were for-hire motor carriers and
14.1 percent (38) were private motor carriers. Of the for-hire motor
carriers surveyed, the majority
[[Page 50014]]
(96.3 percent) were considered over-the-road. In contrast, of the
private motor carriers surveyed, a slight majority (57.6 percent) were
considered local. Additionally, the majority of motor carriers surveyed
were classified as a truckload (92.6 percent) [FMCSA Field Survey
Report (2005), p.4].
Research & Literature Review
As described earlier in Section D, the Agency initiated an
extensive review of scientific literature and research in developing
this rule, which included the use of subject matter experts to assist
in the effort.
The Agency found general consensus within the research that
cumulative wakeful hours have a direct correlation with a person's
alertness and ability to maintain performance. Specifically, longer
wakeful hours result in alertness and performance degradation. The
research conclusions are conflicting, depending upon the type of
research conducted, on the specific number of hours after which the
degradation in alertness and performance adversely affect a driver's
ability to safely operate a CMV.
A 1999 simulator study found only a negligible difference in
fatigue between a typical day (morning to evening) shift of 10- or 12-
hour duty day and a 14-hour day. This same study found that ``a daytime
work schedule of 14-hours on-duty with a 10-hour off-duty period for a
5-day week did not appear to produce cumulative fatigue'' [O'Neill,
T.R., et al. (1999), pp. 37-41].
A more recent study (2000) of New Zealand CMV drivers found ``0.05%
BAC (Blood Alcohol Content) equivalence occurred at between 17 and 19
hours of sleep deprivation for most tests. This means that after around
17 hours of wakefulness, a person's performance capacity is
sufficiently impaired to a level of concern for safety'' [Williamson,
A.M., et al. (2000), pp. 43-44]. Another study of 48 healthy adults
under standardized laboratory conditions found the critical wake period
beyond which performance began to lapse was statistically estimated to
be about 16 hours [Van Dongen, H.P.A., et al. (2003), p. 125]. These
findings are generally consistent with comments by Alertness Solutions,
which emphasized the importance of continuous wakefulness as a
predictor of fatigue [Alertness Solutions, (2005) NPRM Docket
comments].
The role of continuous wakefulness is important in predicting
fatigue, and thereby protecting driver safety and consequently public
safety. Therefore, a duty period provision to control driver work hours
is an important component of the HOS regulatory scheme. There is
consensus among researchers that a schedule that promotes a 24-hour
clock is beneficial in creating regularity of work/sleep schedules.
Researchers also agree that individuals need 7-8 consecutive hours of
sleep per day. The 14-hour duty tour along with a 10-hour off-duty
period meets both of these universally accepted findings. This final
rule promotes movement toward a 24-hour clock and provides all drivers
with the opportunity to obtain 7-8 consecutive hours of sleep per day.
Driver Health Impact
As discussed earlier, an FMCSA driver health team, despite
extensive efforts, found little research to evaluate the specific
impact or association between the specific hours driven or worked and
CMV driver health. One can conclude, based upon the research, that
sleep, along with hours worked, plays a role in a person's overall
health.
If long work hours adversely affect driver health `` which current
research does not clearly indicate `` the 14-hour limit will protect
drivers better than the pre-2003 rule. Drivers ordinarily are not
allowed to extend their duty tour beyond 14 hours. The 14-hour
provision is a substantial improvement over the pre-2003 rule, with its
15-hour limit extendable by the amount of off-duty time taken during
the duty tour, because this provision generally reduces daily work
hours and any associated health effects. However, drivers operating
under the new short-haul rule (described in section J.10) are allowed
to drive up to the end of the 16th hour twice a week. There is no
evidence that this short-haul schedule adversely affects drivers'
ability to drive safely, and there is no available information on the
health implications of an occasional 16-hour workday.
Conclusion
After thorough consideration of the research studies, crash and
operational survey data, and comments to the NPRM, the Agency has
decided to prohibit driving after 14 consecutive hours after coming on
duty. The Agency believes the information is clear on the need to limit
the cumulative hours that a driver may work and continue to drive.
It is the best judgment of the Agency that a 14-hour non-extendable
duty tour period, in conjunction with 11 hours driving and 10 hours off
duty, will reduce driver fatigue, promote driver health, and improve
CMV transportation safety.
J.7. Off-Duty Time
In the NPRM, the Agency requested comments on the extent to which
the increase in the minimum off-duty time from 8 hours to 10 hours
affected driver health, the safe operation of CMVs, and economic
factors in the CMV industry. Of the 452 commenters who discussed the
off-duty requirement, 270 (60 percent) approved of increasing off-duty
time to 10 hours. For drivers who commented, the level of support was
the same; 60 percent of the 366 expressed approval of the increase.
Impacts on Health and Safety
A substantial majority (73 percent) of the comments on the health
and safety impacts of the 10-hour break included positive consequences,
particularly comments from drivers, but also from carriers.
ATA, National Ready Mixed Concrete Association (NRMCA), National
Industrial Transportation League (NITL), the Specialized Carriers and
Rigging Association, the California Highway Patrol (CHP), the
International Brotherhood of Teamsters, and three carriers said the
increase in mandatory off-duty time gives drivers enough time to get 8
hours of sleep as well as to attend to other personal needs. The AFL-
CIO, CHP and a carrier said that the 10-hour off-duty requirement, when
combined with the consecutive 14-hour on-duty requirement, benefits
drivers by putting them on a 24-hour daily schedule. Grammer
Industries, Inc. said that the 10-hour off-duty requirement provides
its drivers with the ability to exercise, take care of personal hygiene
matters, eat meals, and spend time for relaxation. The carrier said
that any break over 10 hours makes drivers out on the road ``nervous''
and causes them stress.
Commenters also pointed out detrimental impacts. Werner Enterprises
and two drivers said that the 10-hour period posed problems for over-
the-road drivers. Werner explained that because the break must be a
full 10 hours, which is often more than a driver needs for sleep and
daily personal maintenance, many drivers are frustrated when they wake
because they must wait an additional 3 to 4 hours before they can go
back on duty. The 10 hours off has little impact on long-haul drivers'
personal or family activities because they are generally away from home
then.
J.B. Hunt also argued that the change had a negative impact on
long-haul drivers. It reported surveying 697 drivers. The survey found
that 32 percent indicated that going from 8 to
[[Page 50015]]
10 hours off was the ``least liked'' part of the new 2003 rule. The
reason given by many was that they must now begin looking for parking
locations by late afternoon or be forced to use ramp areas or other
less safe break locations. Because there is no flexibility in requiring
10 consecutive hours of break time, with the limited exception for
split-sleeper periods that do not allow drivers to take care of their
basic needs, drivers must often try to sleep in less-than-optimal
sleeping conditions. Eleven drivers said that 10 hours off-duty is
overly restrictive for those drivers who do not need 8 to 10 hours of
sleep per night. Over-the-road and team drivers, in particular, found
10 hours too long. Boston Sand and Gravel stated that the rule does not
necessarily lead to increased sleep time, based on personal choices of
the drivers in their use of off-duty time. Massachusetts Concrete and
Aggregate Producers Association, Inc. also argued that 8 hours of rest
was sufficient. ABF stated that most of its drivers would have
preferred retention of the 8-hour rest period when away from home but
liked the 10-hour period at home.
Other commenters recommended a more substantial increase in the
required break. NIOSH reiterated its support for a 24-hour work-rest
cycle of 12 hours on-duty and 12 hours of free time. They also observed
that the 12-on/12-off daily cycle is consistent with common scheduling
practices in other industries that use shifts longer than 8 hours. IIHS
said that the increase in required daily off-duty time is an important
improvement, but it asserted that a 10-hour off-duty requirement still
is inadequate for drivers to obtain restorative sleep and attend to
other daily requirements. AHAS said that solo drivers should have at
least 10 consecutive hours off-duty that are taken in a single block of
time, regardless of whether that off-duty rest time is taken in a
sleeper berth.
McCormick proposed that any rest period equal to or greater than 10
consecutive hours, within a 24 hour period, be considered the driver's
sleep time. Under this approach, rest would be defined as sleep time,
unloading delay time, or delays due to equipment breakdown.
Kimberly Clark agreed that valid science supported a 24-hour work-
rest cycle. However, it recommended reducing the mandatory break from
10 to 9 hours and allowing for a short nap during the duty day.
Economic Impacts
Those carriers that commented generally said that the 10-hour break
has a negative economic impact on them. One carrier stated that its
trucks idle during each rest period, and longer periods reduce motor
life and increase fuel costs. In addition, the trucks are less
productive. Brandt Truck Lines reported an increase in drivers and
vehicles of 15 to 25 percent, depending on schedules and how ``tight''
the operation was under the old regulations. Similarly, Colorado Ready
Mixed Concrete Association stated that for overnight projects and
during peak seasons, companies have had to hire additional drivers to
comply with this provision of the regulation. However, ABF Freight and
another carrier reported minimal impact.
Relatively few drivers commented on the overall economic impact of
the 10-hour off-duty period. One driver stated that the incremental
increase in the minimum required off-duty period resulted in drivers
making less money, as they are usually paid by the mile or trip, and
more off-duty time means fewer miles or trips. Another driver said the
rule increased frustration because it diminishes a driver's income.
FMCSA Response
After thoroughly evaluating all of the information gathered, FMCSA
has decided to require drivers to take a minimum of 10 consecutive
hours off duty.
Crash Data
The Agency has reviewed studies related to crash risk based upon
the hours off duty and opportunity for sleep. Studies of truck drivers,
[Lin, T.D., et al. (1993), p. 9; McCartt, A.T., et al. (1997), p. 63]
point specifically to increased crash risk and recollections of
increased drowsiness or sleepiness after less than 9 hours off duty. A
study by the National Transportation Safety Board [NTSB (1996), p. 37]
found the most critical factors in predicting fatigue were the duration
of the most recent sleep period prior to the crash, length of time
since last sleep period, sleep over the preceding 24 hours, and split-
sleep patterns. Drivers in fatigue-related crashes averaged 5.5 hours
of sleep in the most recent sleep period prior to the crash (6.9 hours
in the last 24 hours), while drivers in non-fatigue-related crashes
averaged 8.0 hours of sleep (9.3 hours in the last 24 hours).
Operational Data
As discussed earlier in Section I, industry surveys found that the
2003 rule, with a minimum of 10 consecutive hours off duty, has
generally improved driver rest (less fatigued) and encouraged movement
toward a 24-hour work/rest cycle. The Minnesota Trucking Association
(MTA) commented that a survey of their members found the 10 hours off
has reduced fatigue, by providing more sleep and promoted better
health. A study directed by FMCSA with VTTI (See Section H), which
began monitoring 82 CMV drivers in May 2004, has found that drivers on
average are getting more than an hour more sleep daily under the 2003
rule. This finding is based upon comparisons of the VTTI data collected
through May 1, 2005, to findings reported in research studies conducted
under the pre-2003 rule.
In addition to the operational data and surveys received from
commenters, drivers submitted comments reporting that under the 2003
rule they have more time at home and obtain more rest, resulting in
reduced fatigue. The Agency believes that the increased sleep reported
through industry surveys, operational data, and commenters can be
attributed to the additional 2-hours off-duty time provided by the 2003
rule.
Research & Literature Review
As mentioned, FMCSA has found general consensus among scientific
researchers regarding the human physiological need for 7-8 hours of
sleep to maintain performance and alertness.
Studies performed in laboratory settings, as well as studies
assessing operational situations, have explored the relationship
between sleep obtained and subsequent performance [Dinges, D.F., &
Kribbs, N.B. (1991), pp. 98-121; Bonnet, M.H., & Arand, D.L. (1995),
pp. 908-11; Belenky, G., et al. (1994), pp. 127-135; Dinges, D.F., et
al. (1997), pp. 274-276; Belenky, G.L., et al. (1987), pp. 1-15 to 1-
17]. These studies generally found poorer performance levels when sleep
is restricted. More recent studies [Balkin, T., et al. (2000), p. ES-8;
Belenky, G., et al. (2003), pp. 9-11; and Van Dongen, H.P.A., et al.
(2003), p. 124] found that even a relatively small reduction in average
nighttime sleep duration (i.e., approximately 6 hours of sleep)
resulted in measurably decremented performance. Another report
[Rosekind, M.R., et al. (1997), pp. 7.2-7.5] concluded that
``scientific data are clear regarding the human physiological
requirement for 8 hours of sleep to maintain performance and
alertness.'' ``Therefore, an average individual who obtains 6 hours of
sleep could demonstrate significantly degraded waking performance and
alertness * * *'' In addition, the authors found the effects of sleep
loss/deprivation to accrue, and stated,
[[Page 50016]]
``* * * data have demonstrated that not only does the sleep loss
accumulate but that the negative effects on waking performance and
alertness also are cumulative and increase over time.''
A past study of 80 over-the-road drivers in the U.S. and Canada,
[Wylie, C.D., et al. (1996), p. ES-10] found that drivers obtained
nearly 2 hours less sleep per principal sleep period than their stated
``ideal'' (5.2 hours versus 7.2 hours).
In a survey [Abrams, C., et al. (1997), pp. 11-12] of 511 medium-
and long-distance truck drivers in the United States, the authors found
no statistically significant differences in the stated rest needs among
various categories of drivers (owner-operator, company driver, regular
route, irregular route, solo, or team). On an average day, a driver
reported needing an average of 7 hours of sleep.
In 1998, an expert panel [Belenky, G., et al. (1998), p. 7]
convened to advise the Agency on potential hours-of-service regulations
for CMV drivers. The panel reported that ``off-duty hours must include
enough continuous time off duty so that drivers are able to meet the
demands of life beyond their jobs and are also able to obtain
sufficient uninterrupted rest.'' In addition, the panel recognized that
``although there is no guarantee that off-duty time will be spent in
sleep, sufficient sleep cannot occur unless there is enough time
allowed for it.'' The panel concluded that, ``the time allotted for
sleep [off-duty time] must be a minimum of 9 [hours].'' The
observations and recommendations made regarding continuous daily time
off duty for CMV drivers supports the Agency's decision in this final
rule to adopt the 10-hour provision.
FMCSA is convinced, based upon the research, that drivers need the
opportunity for 7 to 8 hours of consecutive sleep to maintain alertness
and performance, and reduce fatigue on a daily basis. The Agency
recognizes there are individual differences in the amount of sleep
needed. However, the research overwhelmingly supports that on average
humans require between 7 and 8 consecutive hours of sleep per day to
restore performance. The Agency must ensure that this rule sufficiently
provides for the average sleep needs of all CMV drivers. Establishing a
rule requiring less than the average would result in sleep restriction
over time that would lead to increased fatigue and reduced performance,
thus elevating crash risk and compromising safety.
Driver Health Impact
As discussed earlier, FMCSA found, despite its extensive literature
review, little conclusive research to evaluate the specific impact or
association between the specific hours driven or worked and CMV driver
health. Anecdotally, one can conclude, based upon the research, that
sleep plays a role in a person's overall health. Sleep deprivation has
been associated with poorer health and increased health related
problems, most notably cardiovascular disease, diabetes, and general
health risks associated with obesity. The research supports 6-8 hours
of sleep on average, as having a positive impact upon a person's
health. Therefore, from a driver health standpoint, it is important
that drivers be afforded the opportunity to obtain this amount of
sleep. Based on the research that led to the 2003 rule, FMCSA knew that
short sleep (sleep less than 6 hours) among drivers was a concern from
both a safety and health perspective. As a result, FMCSA increased off-
duty time from 8 to 10 consecutive hours, thereby increasing the
driver's opportunity for sleep by up to an additional two hours per
day. Data, highlighted earlier, from multiple sources confirm that CMV
drivers are obtaining more sleep as a result of the 2003 HOS rule,
averaging more than an extra hour daily.
Conclusion
After thorough consideration of the research studies, crash
analysis reports, operational survey data, and comments to the NPRM, it
is the Agency's best judgment that a requirement for a minimum of 10
consecutive hours off duty is essential to give drivers the time needed
to obtain restorative sleep every day. The Agency believes scientific
research is clear on the need for 7 to 8 hours of sleep to maintain
alertness and performance. Lack of sufficient sleep results in greater
risk of involvement in a fatigue-related crash, and is associated with
health-related complications. To ensure that drivers are afforded the
opportunity to obtain 7 to 8 hours of sleep, the rule must afford a
period of time greater than the minimum required for sleep. Drivers
report being more rested, now that they have been afforded the
opportunity to obtain 7 to 8 hours of sleep due to the increased off-
duty time. Adopting this provision acknowledges the importance of
ensuring that the duration of the most recent sleep period before each
duty tour is adequate to eliminate fatigue on a daily basis. The
Agency's decision to adopt a 10-hour off-duty provision results in no
new cost implications, compared to the 2003 rule.
In addition, the Agency believes that a 10-hour off-duty period
coupled with the 14-hour duty tour will promote movement within the
industry toward a 24-hour clock. A 14-hour non-extendable duty tour, in
combination with the longer off-duty period, enhances the opportunity
for drivers to achieve restorative daily sleep compared to the pre-2003
rule by eliminating the opportunity for the duty period to be extended.
Ensuring that drivers have the opportunity for sufficient sleep,
coupled with moving toward a 24-hour schedule, will reduce driver
fatigue, promote driver health and improve CMV transportation safety.
J.8. The 34-Hour Restart and 60/70-Hour Rules
Introduction
The following summarizes discussions contained in this and earlier
sections of this preamble that are pertinent to the 34-hour restart and
the 60/70 hour rules.
This rulemaking addresses the phenomenon of driver fatigue, i.e.,
the partial and occasional total loss of alertness resulting from
insufficient quantity or quality of sleep. Sleep plays a critical role
in restoring mental and physical function, as well as in maintaining
general health. For most healthy adults an average of 7 to 8 hours of
sleep per 24-hour period has been shown to be sufficient to avoid
detrimental effects on performance.
It has been well established that mental alertness and physical
energy rise and fall at specific times during the circadian cycle,
reaching lowest levels between midnight and 6 a.m., with a lesser but
still pronounced dip in energy and alertness between noon and 6 p.m.
Changes of two or more hours in sleep/wake times cause one to become
out of phase with the circadian cycle.
Circadian de-synchronization results from irregular or rotating
shifts that are not anchored to a 24-hour day (i.e., that start and end
at different times each day), resulting in poor quality sleep and
leading to accumulated fatigue. Sleep loss over several days leads to a
degradation in alertness and driving performance. Sleep loss over
extended periods or during night work can result in cumulative fatigue.
Recovery from cumulative fatigue requires an extended off-duty period.
CMV drivers who repeatedly obtain less than their daily requirement of
sleep incur a sleep debt of some magnitude. In serious cases, the
resulting cumulative fatigue can increase the driver's crash risk.
[[Page 50017]]
Recovery time is needed to erase the effects of sleep loss on
performance, and in aggravated cases, to restore the mind and body to
normal functioning.
FMCSA has determined that the research on CMV drivers supports the
assessment that a recovery period of 34 hours is sufficient for
recovery from cumulative fatigue. The importance of two night (midnight
to 6 a.m.) rest periods was highlighted in the 1998 HOS expert panel
report. The majority of drivers (about 80 percent) are daytime drivers,
who would likely start their recovery period between 6 p.m. and
midnight, and therefore these drivers would have the opportunity for
two full nights of sleep prior to the start of the next work week.
Also, in examining the operational data, FMCSA has determined that many
drivers are extending their recovery periods beyond 34 hours, making it
even more likely that they are getting 2 full nights of sleep. More
than 50 percent of drivers are getting 3 nights of sleep. FMCSA has
concluded from its review of the few scientific studies of recovery
periods that 34 hours off duty provides enough time for drivers to
recover from cumulative fatigue that might occur during multi-day
operations.
In adopting the 34-hour recovery period, FMCSA has taken into
account the weekly accumulation of driving and on-duty time allowed
during each 7- and 8-day period, the adequacy of the 34-hour recovery,
the costs versus benefits of retaining restart, the overwhelming
support of the 34-hour recovery by the transportation industry,
including motor carriers and drivers, the long-term effect on driver
health, and the overall safety aspects of adopting this provision.
Support for Restart
Of the 564 drivers who commented on the 34-hour restart provision,
465 or 82 percent support it. Drivers cited a number of reasons why
they like the 34-hour restart. It is long enough for them to get
adequate rest before returning to work, but it is short enough that it
does not significantly lessen their earnings. The provision gives
drivers more time at home, gives them back the full allowable 70 hours
for the coming 8-day week, and allows drivers to change shifts easily.
Nearly all of the 113 carriers (including owner-operators) that
discussed the 34-hour restart favor it. FedEx Corporation (FedEx) noted
that the ``vast majority'' of FedEx Ground's contractors and their
drivers use the restart provision, and anecdotal evidence from those
contractors supports the 34-hour restart as a way to allow for
sufficient rest and to address any potential HOS compliance issues.
J.B. Hunt Transport said that it had conducted a survey of 697 drivers
and that 67 percent of them thought the 34-hour restart provision was
the ``most liked'' aspect of the new HOS rule. Schneider National, Inc.
said that it had interviewed 46 experienced drivers and they all voiced
support for the 34-hour restart provision, because the restart, in
combination with the 10-hour off-duty requirement, prevents the build-
up of cumulative fatigue.
Crete Carrier Corporation reported that since January 2004, its
drivers more frequently request and receive longer periods of time off
between consecutive days of driving in order to utilize the 34-hour
restart. The carrier said that it now sees drivers proactively
scheduling extended off-duty recovery periods into their workweeks and
returning after these extended periods with ``positive attitudes and
appearing rejuvenated.'' A regional carrier said that the restart
provision benefits drivers by giving them a full day away from work to
rest and relax. One carrier said its drivers haul over-dimensional
loads that they cannot move on Saturday afternoons and Sundays in a
number of states. With the 34-hour restart, however, these drivers get
their 70 hours back after waiting out the weekend. Another carrier
urged FMCSA to keep the restart provision because it directly affects
its ability to retain and recruit drivers.
Eighteen trade associations (trucking and other industries) also
commented in favor of the provision. They cited benefits for both
drivers and carriers. The associations said that the restart provision
provides carriers with additional flexibility and allows increased
productivity. In addition, they said that drivers are able to get home
earlier and more often than they could under the pre-2003 rule.
Opposition to Restart
A total of 109 commenters disapproved of the 34-hour restart
period. Those drivers that opposed the 34-hour recovery period cited a
number of reasons. For example, one thought it is too short to provide
sufficient restorative sleep for short-haul drivers, and another
thought it too long. Other drivers suggested that some carriers are
forcing drivers to sit at truck stops for 34 hours rather than letting
them spend their off-duty time at home. For example, one driver
explained that ``A dispatcher can run a driver out of time (60/70
hours). Then set him/her at a truck stop for 34 hours, 100 miles from
home, then put him/her back on the road for another 60/70 hours. At
least the old way, a driver could get home for a day or two. This way,
the dispatcher can keep a driver out for a long time.''
Public Citizen called the 34-hour restart provision one of the most
harmful aspects of the proposed rule and strongly urged that it be
eliminated. The group said that drivers should not be able to restart
their driving hours by taking only 34 hours off duty. Public Citizen
thought that drivers should be afforded a weekly off-duty period that
includes at least two to three nights of rest after a week of driving.
AHAS also opposed allowing drivers to restart their driving hours
by taking only 34 hours off duty. It stated that drivers should be
guaranteed the opportunity of at least three separate periods of sleep
that are each equivalent to about 8 hours of sleep per night. It
recommended that drivers have approximately 56 to 60 hours off duty
before starting a new tour of duty, so that they can return to a
regular pattern of waking and sleeping. AHAS referenced previous
instances in which FMCSA acknowledged the importance of sleep periods
taken at night. AHAS asserted that no research has shown that drivers
can eliminate their fatigue, recover alertness and performance, and
appropriately expunge an accumulated sleep debt with a 34-hour rest
period. Furthermore, the group said that FMCSA had adopted the 34-hour
restart provision ``in the face of a wealth of contrary evidence * *
*.''
The Insurance Institute for Highway Safety (IIHS) maintained that
there is no scientific basis for the 34-hour restart rule. The group
questioned the applicability of the 1999 study by O'Neill et al., which
FMCSA cited as support for the 34-hour restart provision. IIHS noted
that the study considered the effects of a 58-hour off-duty period, not
a 34-hour period, and said that the study's authors cautioned about
generalizing the results to operations with different characteristics.
IIHS also noted that other studies have not reached the same
conclusions. According to IIHS, a 1997 observational study of over-the-
road drivers found that a 36-hour recovery period was inadequate, and a
2005 analysis of data from a national LTL firm suggested that there may
be increases in crash risk associated with off-duty periods as long as
48 hours.
The Transportation Trades Department of the AFL-CIO also asserted
that the 34-hour restart contributes to the physical exhaustion of
drivers, because they receive only 34 hours off duty before beginning
another ``marathon'' 7- or 8-day work assignment. The union said that
the
[[Page 50018]]
restart provision dramatically cuts into the time drivers who operate
on a weekly schedule would otherwise have to recover, catch up on
sleep, and spend with their families. The International Brotherhood of
Teamsters claims that any benefits of the 10-hour rest period and the
14-hour tour of duty provision are offset by the increase in driving
time and the use of the 34-hour restart provision. The union asserted
that the 34-hour restart has become mandatory for most drivers who are
not protected by collective bargaining agreements. The union said that
their collective bargaining agreements do not provide for the use of
the 34-hour restart. Despite this fact, the union does not think that
the companies for which its members work have been competitively
disadvantaged.
Elisa Braver, University of Maryland School of Medicine, asserted
that there is an absence of scientific evidence that the cumulative
sleep deficits and fatigue incurred by working 60 hours can be remedied
by having 34 hours off duty. She said that the scientific evidence
cited by the Agency in support of the 34-hour restart is marred by
small numbers, inapplicability to the driving population, and failure
to study the effects of having 34 hours off after working according to
the schedule permitted by the rule. As an example, Braver said that the
study cited by O'Neill [O'Neill, T.R., et al. (1999)] featured small
numbers of volunteers in driving simulators following a schedule unlike
that of typical drivers who had 58 hours off between five-day work
shifts. Braver cited a 2005 study which purportedly showed that 34
hours is an insufficient period for recovery [Park, S-W., et al.
(2005)]. Braver cited another study [Belenky, G., et al., (2003)] that
she said indicated recovery from sleep deprivation can take longer than
48 hours.
Adequacy of 34-Hour Recovery To Eliminate Fatigue
By a large margin, the commenters who directly discussed the effect
of the restart on fatigue said that it is long enough to provide
sufficient restorative sleep, regardless of the number of hours worked
prior to the restart. Of the 132 commenters who addressed the topic,
113 said that 34 hours is long enough to provide sufficient restorative
sleep.
The Owner Operator Independent Drivers Association (OOIDA) noted
that none of its members had reported needing more than two consecutive
nights to obtain restorative sleep. The association said that drivers
who use their 10 hours off duty to get sufficient restorative sleep
never accrue a sleep deficit, so they are more than prepared to operate
safely after the 34-hour restart. ATA said that the restart provision
has improved the sleep/rest recovery period for drivers and enhanced
their quality of life. It believes that the provision encourages
carriers to more regularly schedule extended off-duty periods for
drivers and that drivers are seeking to take that time off as a result
of the restart provision. ATA also noted that the provision has helped
to avoid the shifting of daytime to nighttime schedules, which research
indicates can affect circadian rhythm and decrease alertness. CR
England, Inc. said that the 34-hour restart offers irregular-route,
long-haul drivers great relief from fatigue and sleepiness. The carrier
noted that the restart is particularly beneficial to its drivers who
want the rest but prefer to not spend their off-duty days away from
home. The carrier called the restart provision a ``win-win situation
for the driver'' because it allows higher earnings, enhanced safety,
and improved family morale.
Alertness Solutions provided a lengthy commentary on the rule. It
stated that the 34-hour period provides sufficient time for two 8-hour
sleep periods and one 18-hour period of intervening wakefulness that
should allow recovery from a cumulative sleep debt. The daily 10-hour
off-duty period is intended to minimize or eliminate any acute sleep
loss, so any cumulative sleep debt that might exist under the HOS rule
should be minimal or none. Any sleep debt that might occur under the
rule should be sufficiently ``zeroed'' in the context of the 34-hour
restart period. Alertness Solutions also argued that there are no
scientific data that specifically address the number of work hours per
week (or per month or per year) that would be required to cause fatigue
serious enough to reduce performance, alertness, or safety. However,
limiting the number of work hours in a specified timeframe is a common
approach used in scheduling practices and in regulatory policies to
address fatigue. Often these weekly limitations are calculated based on
the daily limitations. For example, Alertness Solutions pointed out
that a 14-hour duty limit, worked for 5 days yields a total of 70 hours
of work. If considered in terms of historical practice related to a
five-day workweek and two days off for a ``weekend,'' 70 hours of
cumulative work hours in a 7-day period is consistent. As reflected in
the FMCSA rule, these total work-hour limitations are even more
conservative than this calculation. Also, because the daily limitations
on duty and the provided off-duty rest are intended to minimize or
eliminate acute fatigue, they represent a rational basis for
calculating the cumulative work hours total. A core premise in the
weekly work-hour limitations is that they both restrict the total work
hours and provide a recovery period within a certain timeframe. The 34-
hour restart specifically addresses the recovery opportunity. Although
there is no scientific basis for the weekly work-hour limitations,
there are scientific data to address the recovery issue. Alertness
Solutions also said there are some studies that have consistently
demonstrated that two nights of sleep result in performance and
alertness recovery following significant sleep deprivation.
AHAS, however, said that FMCSA did not (and could not) demonstrate
that drivers utilizing the 34-hour restart provision are no more
fatigued and are just as safe as drivers were when operating under the
prior regulatory regime. AHAS claimed that FMCSA ``simply relied upon
its rulemaking authority to pronounce new, more demanding HOS
requirements and to assert, without specific support anywhere in the
record, that this expansion in driving hours and reduced time off would
nevertheless somehow generate a net gain in safety.''
IIHS agreed that FMCSA ignored studies showing an association
between long driving hours and reports of falling asleep at the wheel
of a large truck. IIHS added that among drivers it had interviewed,
those reporting work hours longer than 60-70 per week, or other hours-
of-service violations, were 1.8 times as likely to report falling
asleep while driving during the month prior to their interviews as
drivers who reported they worked fewer hours.
IIHS also critiqued Alertness Solution's comments. IIHS believes
that the studies it referenced were not based on commercial vehicle
drivers, but were primarily experiments that examine the effects on
simulated performance of continuous hours of wakefulness, not time on
task. IIHS said that the Alertness Solution commentary did not consider
the range of factors that may affect sleep debts among truck drivers
(e.g., split rest time in a sleeper berth) and their ability to get
adequate recovery sleep in the real world. For example, IIHS noted that
for many drivers the 34-hour recovery period occurs on the road rather
than at home.
Public Citizen thought that none of the research cited by FMCSA
justifies a restart that provides for only two sleep periods,
regardless of the time of day.
[[Page 50019]]
The group asserted that the minimum weekly recovery period that is
supported by studies cited in the NPRM and earlier rulemaking notices
is two consecutive nights of sleep. According to Public Citizen, the
1999 simulator study concluded that two full nights and one intervening
day--about 32 hours off duty--would be a minimum restart period,
although the study actually studied 58-hour recovery periods and never
looked at recovery periods brief as 32 hours. The group also said that
another study cited by the Agency, performed in 1997, found that when
participants using simulators received 36-hour and 48-hour recovery
periods after four workdays, ``there was no objective evidence of
driver recovery.'' Public Citizen also said that a 1997 literature
review, which attempted to assess scientific support for a 36-hour
restart, found no such support, and in fact found only one study even
dealing with an operational schedule that allowed such a brief weekly
recovery. Public Citizen quoted the authors that this was because
``such a short reset period would result in schedules that would exceed
current hours-of-work regulations in most countries.''
Regarding the current 24 consecutive hour restart for utility
service drivers, groundwater well transporters, and construction
material truck drivers, which is not affected by this rule, Public
Citizen noted that in 2000 FMCSA conceded that it ``ha[d] found no
sleep or fatigue research that supports any of the current exceptions
or exemptions, including the 24-hour restart provisions.'' The group
said that at that time FMCSA recommended that these drivers be provided
a weekly recovery that included at least two consecutive nights of
sleep.
The California Highway Patrol said that the 34-hour restart rule
should be increased for all CMV drivers from 34 consecutive hours to 58
consecutive hours. This would allow a driver time to commute, a minimum
of three uninterrupted 8-hour rest periods, and 2 full days off duty
before returning to work with zero hours on their 60/70-hour rule.
Several drivers suggested that the restart period should be shorter
(e.g., 24 hours) when drivers are on the road. One driver said,
``Spending 34 hours (less sleeping time) doing nothing in a truck stop
is more fatiguing than working.'' Another driver suggested that the
restart period should be only 24 hours for team drivers.
Length of the Recovery
Nearly half of the 87 commenters who discussed the appropriate
length of the restart period suggested that it should be 24 hours; 48
hours was the next most popular choice. Sixteen commenters voiced
approval for 34 or 36 hours.
Use of Restart
FMCSA requested information on how frequently the restart provision
is being used. Ninety-five commenters responded, of whom 68 said that
restart is being used weekly. Sixteen commenters said that the restart
provision is being used one to three times per month. OOIDA indicated
that among the members it surveyed, the 34-hour restart is the most
consistently used feature of the current HOS rule, but it would be
inaccurate for FMCSA to assume that all drivers are continuously
maximizing use of the weekly 60 or 70 hours by using the 34-hour
restart. NITL believes that substantial and/or continuous use of a
``21-hour day'' by drivers is a hypothetical result, rather than a
likely consequence of the 2003 rule in the real world. NITL goes on to
state that as a practical matter drivers must take breaks and complete
non-driving tasks over the course of the day, such as meals and
mandatory vehicle inspections. IIHS stated that among the drivers it
interviewed, more than 90 percent said they used the restart provision
during 2004. IIHS said a large majority reported that the restart
provision was part of their regular schedule. J.B. Hunt Transport
reviewed the work record of 80 randomly selected over-the-road drivers
for a 30-day period, and found that 74 percent of them used the 34-hour
restart at least once during that period. On average, the drivers
accumulated 62.25 hours per eight-day period. Werner Enterprises, Inc.
said that its drivers use the 34-hour restart extensively and that they
report feeling adequately rested after doing so. Schneider National
said that 26.1 percent of its driver breaks are between 34 and 44
hours.
Interaction of Weekly 60/7 and 70/8 Rules With Restart
FMCSA explained in the 2005 NPRM that, under both the pre-2003 and
2003 rules, most drivers are prohibited from driving after reaching a
maximum of 60 hours of on-duty time in any consecutive 7-day period, or
70 hours in any consecutive 8-day period. Of the 106 commenters who
addressed the topic, 80 (75 percent) expressed opposition to the weekly
limits and particularly their interaction with the restart provision.
IIHS stated that, although the rule purports to maintain the prior
60/70-hour limits on ``weekly'' driving, the restart provision actually
allows drivers to log up to 88 hours of driving during an 8-day period
(an increase of up to 30 percent), and up to 77 hours of driving during
a 7-day period (an increase of up to 25 percent). IIHS claims that many
drivers have dramatically increased their multi-day driving and work
time, and they may do so week after week. Such a change should be
allowed only if there is convincing scientific evidence that beginning
another week of driving after such a short period of rest will not
adversely affect safety.
Public Citizen agreed that weekly driving and on-duty time would be
radically increased under the rule. Under 7- or 8-consecutive-day
limits, the most exhausted drivers, that is, those driving the daily
maximums repeatedly, would in practice receive the longest weekly
recovery period, while those driving and working less would reach the
60-hour or 70-hour limits later in the week and have a shorter weekly
recovery time. The 34-hour restart, on the other hand, has the effect
of allowing truckers who maximize their driving to drive more per week
with less required recovery time. Public Citizen said scientific
studies show that as drivers log more hours on the road over multiple
days, their performance declines. They concluded that drivers should
not be able to accrue more than 60 hours of driving over 7 consecutive
calendar days or more than 70 hours of driving over 8 consecutive
calendar days. Fewer hours of driving would further improve safety.
In contrast, Alertness Solutions stated that once any cumulative
sleep debt has been erased through recovery sleep, an individual should
be considered rested and without any acute sleep loss or sleep debt.
From a physiological perspective, after a 34-hour restart period, a
driver would be considered to have zero sleep loss, acute or
cumulative, and be appropriately rested for duty. Alertness Solutions
suggested that any subsequent duty hours accrued would be accrued from
a rested or ``zeroed'' sleep loss calculation and added to the
following total of work hours. Adding these subsequent work hours
retroactively to a ``weekly'' total, after a recovery period, is
misleading and inappropriate. Alertness Solutions said the weekly
timeframe is an arbitrary constraint in this physiological context.
While the total hours can be calculated to be higher in a ``week'' by
adding retroactively, this ignores the physiological status of a driver
who should be rested and ready for duty. In fact, the primary objective
of a recovery or restart period is to ``zero out'' any
[[Page 50020]]
accumulated fatigue effects and have a rested operator prepared for
duty.
Limits on Use of Restart
The NPRM asked whether a driver who has already exceeded 60 hours
on duty in 7 days, or 70 hours in 8 days, should be permitted to
utilize the 34-hour restart at any time, or should instead be required
to take enough days off duty to be in compliance with the 60-/70-hour
provision before beginning the restart period. An Agency policy
directive issued on November 25, 2003, provides guidance to roadside
law enforcement officials on how to implement the 34-hour restart
provision, when drivers have exceeded the 60/70 hour rule. The current
policy guidelines require drivers to come into compliance with the 7/8-
day weekly duty time before applying the 34-hour restart provision.
J.B. Hunt Transport argued that if the purpose is to punish the
driver for working over the 60 or 70 hours (which they can do without a
violation as long as they do not drive), then the driver who exceeds
the 60 or 70 hours should be required to wait before using the restart
provision. On the other hand, if the purpose is to ensure the driver is
rested and safe, then many of the current studies and reports would
support allowing the restart at any time. J.B. Hunt urged FMCSA to
clearly indicate which of these two purposes it has chosen. The carrier
said that the current regulatory wording is not consistent with the
interpretive guidance that has been issued by the Agency.
OOIDA questioned FMCSA's interpretation of the 2003 rule, which
appeared to mean a driver who has driven for 59.9 hours in 7 days or
69.9 hours in 8 days, respectively, could use the 34-hour restart, but
a driver who has driven 60.1 or 70.1 hours would be required to go off
duty for as many as three days before being allowed to return to duty
or begin a 34-hour restart period. OOIDA said it is unaware of any
study that supports the conclusion that drivers whose driving time is
separated by just minutes need such dramatically different amounts of
off-duty time to obtain restorative sleep. OOIDA asserted that a driver
could obtain more than sufficient rest during a 34-hour restart
regardless of whether the driver has exceeded the 60- or 70-hour rule.
OOIDA asked FMCSA to withdraw its interpretation of the rule or to
change the language of the rule. FedEx said that if a driver exceeds
the rule's limits, the driver is in violation and should be held
accountable. However, if a driver exceeds the rule's limits, either in
the non-driving mode, which is legal, or in the driving mode, which is
not, the 34-hour restart should reset the driver's clock to zero. FedEx
noted that otherwise there is no foundation for enforcement. Because a
driver is only required to carry the previous seven days' logs, it is
impossible for a field enforcement officer to look back far enough to
know if a reset was legitimate or not. Because a driver cannot legally
drive after 70 on-duty hours in eight days or 60 on-duty hours in seven
days, and given the impracticality of enforcement, FedEx Freight
proposed that the restart be applicable to those cases in which a
driver exceeds the 70-hour or 60-hour limit prior to the restart.
Robert Transport suggested that a driver should be allowed to use
the 34-hour restart in any circumstances. The carrier said that when
drivers exceed their weekly limit, it is usually because of
unpredictable events such as a snowstorm, an unusually long wait at a
border crossing, or an excessive loading or unloading time. The carrier
did not think that drivers should be penalized in these situations by
having to wait before utilizing the restart.
In contrast, the CHP asserted that drivers must be in compliance
with the applicable cumulative total before using the restart
provision. The CHP said that if a driver is allowed to use the 34-hour
restart provision without regard to the 60/70-hour rules, the driver
could easily work in excess of 98 hours in an 8-day period before
driving is prohibited. A regional carrier also said that drivers should
have to wait until they are below the 60/70-hour period before using
the 34-hour restart. Otherwise, a carrier could send a long-haul driver
back out on the road after only one day off, which the commenter said
was insufficient time off.
Economic Impact of Eliminating Restart
FMCSA requested comments on the impact of eliminating restart in
terms of productivity, annual revenues, and operational costs.
Responding to FMCSA's request, 68 commenters (49 drivers, 18 carriers,
and one trade association) indicated that eliminating the 34-hour
restart would have a negative economic impact on the trucking industry.
J.B. Hunt Transport said that eliminating the restart provision
would have a negative impact on the company, but the company had not
quantified it. A sample of its drivers averaged 62 hours on duty in 8
days, which indicated that the drivers were not using the restart
provision to work the maximum number of hours possible. Given that
fact, J.B. Hunt reported that eliminating the restart provision would
not necessarily reduce the number of hours that its drivers worked each
week. Roehl Transport estimated that eliminating the restart provision
would reduce its productivity by 1 to 2 percent. The carrier believed
that it would also incur higher fuel costs, because drivers would be
waiting at truck stops more often and would burn the fuel to maintain
comfortable cab temperatures. The carrier also thought that drivers
would spend more money for meals and other living expenses, because
they would be spending more time waiting while out on the road. A
regional carrier of agricultural products noted that there are only
certain times of the week when its drivers get tight on hours under the
rolling weekly limits on hours. The carrier said that if the restart
provision were eliminated, it would have trouble hiring drivers to work
for only a few days a week. It also believed that its overhead costs
would increase.
Brandt Truck Line, a short-haul carrier, said that eliminating the
restart provision would not affect local carriers operating under the
60/70 weekly limit, but it would hurt the productivity of local
operations working under the 70/8 limit. The carrier noted that those
carriers either would have to revise their local Monday-to-Friday work
schedules to be four days (14 hours each), or would have to reduce the
hours of each 5-day driver from 14 hours per day to 11.67 hours per
day. The carrier would then have to hire one additional driver for
every seven drivers that it currently employs. Perishable Distributors
of Iowa indicated that eliminating the 34-hour restart would hurt it
financially because it would not be able to use the 16-hour rule as
often. (As provided by Sec. 395.1(o)(3), drivers who have returned to
their normal work-reporting locations for the five previous tours are
allowed to operate up to the 16th hour once a week, unless they take a
34-hour restart during that week.) The carrier said it would also have
a labor issue, because it would have to shorten its routes and create
more of them. The drivers would be working fewer hours, creating
financial hardships.
Safety and Health Impact of Eliminating Recovery
FMCSA asked about the health impact and the safety impact of
eliminating the 34-hour restart. Both carriers and drivers said that
elimination of the restart provision would be harmful to driver health.
Werner Enterprises and Roehl Transport stated that elimination of
the 34-hour restart would likely have a deleterious effect on driver
health, and
[[Page 50021]]
would encourage drivers to adjust their work schedules to let them run
every day without taking a day off. For long-haul drivers it would mean
more non-productive sitting and waiting time during a week in a truck
stop. The carriers asserted that wasting time results in a host of
medical and life-style issues, including over-eating, frustration,
stress, and a general feeling of job dissatisfaction in an industry
where turnover is a significant issue. Drivers away from home during
the week need to be allowed to work as much as they would like within
the confines of safe operations. Maverick Transportation had no data to
support a negative impact on health and safety but believed that
elimination would have a big impact on driver lifestyle and morale.
J.B. Hunt Transport said that removing the restart could have an
adverse affect on drivers' health and could also negatively impact
crash frequencies, because its drivers appear to use the restart as
much to reduce stress and to obtain longer periods of rest when needed
as they do to simply work and drive longer. Two carriers stated the
restart impacts drivers' health positively because they start fresh
after the period of time off that is spent at home the majority of the
time. Two other carriers, however, noted that it would have no impact.
One driver thought that eliminating the restart provision would
contribute to older, experienced drivers leaving the industry. The
resulting increase in the number of newer drivers would increase the
number of crashes, fatalities, and injuries. Another driver said that
elimination of the provision would increase the number of drivers who
violate the HOS rules. Two drivers noted that the restart allows them
to stay on a regular 24-hour cycle, and changing it would disrupt the
cycle. Three drivers stated that elimination would increase driver
stress. One driver stated that by the end of the 8-day cycle, drivers
are working odd hours because they are trying to work around what they
did 8 days before. If they start over after being off duty for 34 hours
they will not be punished for working the week before. Without the
restart they must sometimes drive a short day and work long hours
during the early morning hours in order to make deliveries. This
disrupts their sleep cycle and directly contradicts what the new
regulations are supposed to correct.
Finally, as described earlier under ``Opposition to Restart,''
several groups, including Public Citizen, AHAS, and IIHS expressed
strong opposition to the restart provision.
FMCSA Response
Based on the scientific data and comments it has received, FMCSA
has decided to prohibit drivers from driving after reaching a maximum
of 60 hours of on-duty time in any consecutive 7-day period, or 70
hours in any consecutive 8-day period. The Agency will also allow any
7- or 8-day period to end with the beginning of any off-duty period of
34 or more consecutive hours. FMCSA has determined that a 34-hour
recovery period permits a majority of drivers to have enough time for
two uninterrupted nights of 8 hours recovery sleep before returning to
work in a new multi-day duty period. While the research on adequate
recovery periods is somewhat limited, there is general agreement that
two nighttime periods (midnight to 6 a.m.) are sufficient for full
recovery from fatigue. Data reviewed by FMCSA shows that 22 percent of
CMV driving takes place at nighttime, between midnight and 6 a.m.
[Campbell, K.L, & Belzer, M.H. (2000), p. 115]. Many of these drivers
would have to sleep during the day. However, the 34-hour recovery
period would give drivers who perform the other 78 percent of driving
(between 6 a.m. and midnight) an opportunity to obtain two nights of
recovery sleep prior to starting the next work week. In adopting the
weekly limit and recovery provisions, the Agency considered all
relevant research, appropriate economic factors, and comments received
on the NPRM addressing driver health and public safety.
In the 2000 NPRM, the Agency proposed to require a weekly off-duty
period or ``weekend'' which would have imposed a regulatory requirement
for a weekly off-duty period containing two midnight to 6 a.m. blocks
for all CMV drivers (65 FR 25562). In the 2003 rule, FMCSA explained
that it opted for a 34-hour restart provision in light of the concerns
expressed by commenters that the proposed ``weekend'' requirement would
increase daytime congestion and accident risks and produce irregular
sleep schedules (68 FR 22477). Commenters pointed out that the
``weekend'' proposal ``assumes that every driver is subject to weeklong
sleep deprivation.'' FMCSA admitted that it ``may have overreached
trying to prevent the most extreme abuses by imposing restraints on the
whole driver population'' [Id.].
Studies indicated that cumulative fatigue and sleep debt can
develop over a weekly period, and at least two nights of sleep are
needed to ``restore'' a driver to full alertness [Belenky, G., et al.
(1998), p. 13; Jovanis, P.P., et al. (1991), p. 2; Linklater, D.R.
(1980), p. 198; Williamson, A.M., et al. (1994), p. 104]. The Agency
determined that the 34-hour recovery period, which is based on a full
24-hour period plus an additional 10-hour period available for sleep,
is the minimum restart which would provide adequate restorative rest.
FMCSA explained in the 2003 rule that it considered a number of
competing factors and opted for a uniform rule that ``represents the
best combination of safety improvements and cost containment that can
realistically be achieved'' (68 FR 22457). In the 2005 NPRM, FMCSA
reiterated that, ``The 34-hour restart was considered as a flexible
alternative to the ``mandatory weekend'' proposed in the 2000 NPRM * *
* [70 FR 3348].
The D.C. Circuit criticized FMCSA for neither acknowledging nor
justifying that the 2003 rule ``dramatically increases the maximum
permissible hours drivers may work each week'' (Public Citizen, at
1222-1223). In the 2005 NPRM, the Agency explained that the restart
provision provides an opportunity for increases in the total hours of
permissible on-duty time in a 7-day period, after which a driver may
not drive a CMV, from 60 hours to 84 hours. It also provides an
opportunity for increases in the maximum driving time permitted in a 7-
consecutive-day period (from 60 hours to 77 hours). Likewise, the
restart provision provides an opportunity for increases in the total
hours of permissible on-duty time in an 8-day period, after which a
driver may not drive a CMV, from 70 hours to 98 hours and, provides an
opportunity for increases in the maximum driving time permitted in an
8-consecutive-day period (from 70 hours to 88 hours). A number of
advocacy groups argue that these extra on-duty and driving hours
virtually guarantee that drivers are far more fatigued under the 2003
rule than under the pre-2003 regulations.
Several commenters argued against retaining the recovery period.
Their comments can be placed into three related categories: (1) Two
nights of sleep are needed for full recovery; (2) science does not
support the 34-hour recovery period; and (3), the recovery period
should be eliminated or increased in length due to the potential for
drivers to significantly increase their daily and weekly working hours.
The Agency decided to adopt a 34-hour recovery period based on an
extensive scientific review of the literature, data, and comments.
Adopting a recovery period is based upon seven main points: (1) Impacts
of potentially longer weekly hours; (2) Operational data; (3) Economic
impact of the rule; (4) Review
[[Page 50022]]
of the literature regarding recovery and fatigue; (5) Public comments;
(6) Public safety and operational concerns and (7) Health impacts of
eliminating or modifying the recovery provision.
Impacts of Potentially Longer Weekly Hours
Some of the commenters paint a picture of drivers working every
additional hour allowed by the 34-hour recovery provision, and
accumulating dangerous levels of fatigue. As indicated by the docket
comments of motor carriers and industry associations, these images have
little to do with the real world. Information collected and analyzed by
FMCSA shows that most drivers are taking longer recovery periods than
the minimum 34-hour recovery period that FMCSA is establishing under
this rule. FMCSA believes the average driver is not, and cannot
realistically, drive and work the longer weekly hours, on a regular
basis, as described by some of the commenters.
The 2005 FMCSA Field Survey (see Section I.1) shows that between
July 2004 and January 2005, 393 drivers used 1,411 recovery periods.
The survey found that 95 percent of recovery periods exceeded 34 hours
in duration. Figure 8 shows that 50 percent of the recovery periods
were longer than 58 hours, in contrast to 5 percent that were only 34
hours long. The data appear to confirm that, in fact, a majority of
drivers are obtaining two midnight to 6 a.m. sleep periods.
Figure 8.--Recovery Periods
[Local & OTR]
------------------------------------------------------------------------
Restart period (hours) Instances Percent
------------------------------------------------------------------------
34.............................................. 66 ..........
35 to 58........................................ 635 45
>58............................................. 710 50
-------------
Total......................................... 1411 100
------------------------------------------------------------------------
Source: 2005 FMCSA Field Survey.
In the 2005 NPRM, the Agency acknowledged that a driver using the
34-hour recovery period could work a maximum of 77/88 driving hours or
84/98 driving and other on-duty hours depending upon which weekly rule
the motor carrier operated under (i.e., 60/7 or 70/8). It is highly
unlikely that drivers could, in practice, continually maximize their
driving and on-duty time and minimize their off-duty time. Many of the
larger carriers that commented to the 2005 NPRM agreed that in most
instances drivers do not consistently have the opportunity, nor are
they taking it, to accumulate the maximum amount of driving and on-duty
hours that are theoretically allowed under the 2003 rule. For example,
J.B. Hunt Transport said that a sample of its drivers averaged 62 hours
on duty per 8 days under the 2003 HOS rule, which indicates that the
drivers are not using the restart provision to work the maximum number
of hours possible. Werner Enterprises, Inc. also, said that there has
been no significant change in the number of hours worked by its drivers
as a result of the 34-hour restart. FMCSA's Field Survey showed the
average weekly (7-day) hours worked by CMV drivers is 61.4 hours.
To reach the maximum driving or driving and on-duty hours requires
that nearly perfect logistics for picking up and delivering a load are
routinely in place; in other words, total elimination of waiting time
to load, mechanical and equipment problems, and traffic- and weather-
related delays. Additionally, as explained in this rulemaking, FMCSA
and other independent survey data collected since the 2003 rule was
adopted indicate that drivers are not, in fact, maximizing their
driving hours or total on-duty time, nor do they routinely take the
minimum number of off-duty hours. In view of these facts, drivers will
not routinely accrue the maximum weekly driving and on-duty hours
feared by some commenters.
This is not surprising. As indicated above in section J.5, driving
and on-duty hours under the 2003 rule would not be expected to increase
suddenly unless there had been an equally sharp spike in demand for
trucking services. Although the U.S. economy is expanding, there was no
unprecedented eruption of demand for transportation in 2004 and 2005
that might have overwhelmed the normal, measured growth of the motor
carrier industry and forced drivers to maximize their work hours in
order to handle a huge volume of new cargo. The data FMCSA has
collected bear this out. While some drivers may occasionally drive the
maximum hours allowed by the 34-hour restart rule, most will continue
to work about the same number of hours they did before the 2003 rule.
According to commenters, the great advantage of the restart provision
is not the increased work hours it allows, which are not regularly
used, but the scheduling flexibility it gives motor carriers and the
added time at home it gives drivers.
Operational Data
As mentioned earlier, the 2005 FMCSA Field Survey (see Section I.1)
shows that between July 2004 and January 2005, 393 drivers used 1,411
recovery periods. The survey found that 95 percent of recovery periods
exceeded 34 hours in duration. Figure 8 shows that 50 percent of the
recovery periods were longer than 58 hours, in contrast to 5 percent
that were only 34 hours long. The data appear to confirm that, in fact,
a majority of drivers are obtaining two midnight to 6 a.m. sleep
periods.
2004 FARS data suggest that fatigue-related crashes, as a percent
of all fatal truck crashes, have decreased under the 2003 rule.
Similarly, carriers commenting on the 2005 NPRM generally cite either
stable or decreasing crash rates (see Section H-Crash Data). FMCSA
agrees with many commenters that the limited data available does not
provide a definitive picture of the impact the 2003 rulemaking has had
on fatigue-related CMV crashes. However, the preliminary data reported
and reviewed to date does suggest that fatigue related crashes have
decreased as a result of the 2003 rulemaking.
Economic Impact of the Rule
The safety and health effects of modifying or eliminating the
recovery provision need to be weighed against the significant economic
costs that would be incurred by the transportation industry. As
discussed in detail in the RIA accompanying this rule, increasing the
restart period to 44 hours would result in an extremely high cost
relative to benefits. Specifically, the annual costs to implement a 44-
hour recovery period were estimated at approximately $600 million. The
cost to eliminate the 34-hour recovery provision in isolation, or with
no other HOS-related changes implemented, was even higher, with annual
costs more than $1.5 billion from productivity losses to motor
carriers, while safety benefits were estimated at less than one-tenth
the cost. In summary, the cost to modify the recovery provision was
estimated to be significant, which is due in part to its extensive use
by the industry, as discussed in detail throughout this rulemaking.
As discussed further in this section, an analysis of survey data by
Campbell and Belzer [Campbell, K.L., & Belzer, M.H. (2000), p.115]
found that the average commercial truck driver drives approximately 22
percent of his or her weekly driving time during the midnight to 6:00
a.m. period. While the economic impacts of restricting driving during
the midnight to 6:00 a.m. period were not explicitly measured as part
of this rulemaking, such a restriction would undoubtedly result in
significant economic impacts to the motor carrier industry, given that
22 percent of current driving time would have to be
[[Page 50023]]
shifted to the remaining 18 hours of the workday, or that period in
which most highway congestion already occurs. These impacts would come
in the form of both reduced safety benefits as well as new operational
costs to carriers. Numerous comments submitted to the docket in
response to the 2000 HOS NPRM spoke to this point. For instance,
comments submitted by the National Private Truck Council, American
Trucking Associations, Watkins-Shepard Trucking, the National
Association of Small Trucking Companies, and many others, noted that
restrictions placed on nighttime driving would force trucking companies
to place more of their trucks on public roadways during the already
congested daytime hours. Additionally, some carriers would have to
purchase additional trucks that would be required to operate during the
daytime period, in those instances where a single truck was previously
utilized by two drivers operating on separate day and night schedules.
As a result, all of these trucks would be operating at a portion of the
day when traffic congestion is the worst, resulting in an increase in
truck-related crashes and thereby offsetting any potential safety
benefits resulting from a reduction in fatigue-related truck crashes
from nighttime driving restrictions. Such a restriction would also
impose major operational costs to those segments of the industry that
use nighttime runs to support daytime operations. For instance, a
sizeable portion of the driving done during the nighttime period is
performed by line-haul drivers of LTL companies, which haul freight
between terminals during the midnight to 6 a.m. period in preparation
for local delivery services the following day.
Review of the Literature Regarding Recovery and Fatigue
FMCSA is convinced that the combined impact of today's rule,
including the 34-hour recovery period, increases the safety to CMV
drivers and is not deleterious to their health. Other provisions of
this rule restrict the total on-duty time to 14 hours that cannot be
extended by breaks, require drivers to take 10 consecutive hours off
duty before beginning a new duty period, and eliminate the split
sleeper-berth provision, by requiring that drivers utilize one sleeper-
berth period of at least 8 hours. These provisions limit duty time,
while affording ample time for drivers to obtain the 7 to 8 hours of
sleep that the majority of the research indicates is sufficient to
restore a driver to full alertness on a daily basis (see Combined
Effects discussion, section J.11).
FMCSA believes the 34-hour recovery period serves as an additional
safety benefit that affords a majority of drivers two nights of sleep
recovery, which should sufficiently enable drivers to eliminate or
``zero out'' any cumulative fatigue that may occur over several days.
While some research suggests that a 24-hour period is sufficient to
reduce cumulative fatigue [Bonnet, M.H. (1994), p. 62], most research
agrees that optimal recovery occurs when there are two consecutive 8-
hour sleep periods from midnight to 6 a.m. [Dinges, D.F., et al.
(1997), p. 276; Rosekind, M.R. et al. (1997), p. 7.3]. Under the 34-
hour recovery period, 78 percent of the drivers will be able to obtain
two consecutive nights of sleep, and those whose schedules do not
permit night sleep will at least be provided with two 8-hour sleep
periods and some schedule regularity. However, as stated by FMCSA's
2000 NPRM expert panel, ``If the work shift ends late in the evening,
e.g., 11:30 p.m., it is conceivable that the driver could be in bed by
midnight if there is an adequate place to sleep nearby. Under these
circumstances the total recovery time period could be as short as 31 or
32 hours and still allow for two uninterrupted time periods between
midnight and 6:00 a.m.''
Additionally, nighttime drivers will be less fatigued on a daily
and weekly basis, compared to the pre-2003 rule, through the combined
effects of the provisions of the rule being enacted today (see Combined
Effects, section J.11). While the two consecutive 8-hour sleep periods
that some night drivers will utilize for sleep are not ideal, today's
rule will limit the build-up of cumulative fatigue; hence, the two 8-
hour sleep periods give drivers an adequate opportunity to help
minimize such acute and cumulative fatigue, regardless of their driving
schedule.
FMCSA has determined that, in general, recovery time periods must
take into consideration the necessity for overcoming cumulative fatigue
caused by sleep debt. [Dinges, D.F., et al. (1997), p. 267; Balkin, T.,
et al. (2000), p. ES-8; Belenky, G., et al. (2003), p. 11; Van Dongen,
H.P.A, et al. (2003), p. 125] Fatigue resulting from sleep loss is
usually characterized as acute, resulting from a single insufficient
sleep period, or cumulative, resulting from two or more insufficient
sleep periods [Rosekind, M.R., et al. (1997), p. 7.2]. Rosekind
describes three types of sleep loss: ``Sleep loss can occur either
totally or as a partial loss. Total sleep loss involves a completely
missed sleep opportunity and continuous wakefulness for about 24 hours
or longer. Partial sleep loss occurs when sleep is obtained within a
24-hour period but in an amount that is reduced from the
physiologically required amount or habitual total. Sleep loss also can
accumulate over time into what is often referred to as ``sleep debt.''
Sleep loss, whether total or partial, acute or cumulative, results in
significantly degraded performance, alertness and mood'' [Id.].
Under today's rule, most drivers have an adequate opportunity to
limit the accumulation of fatigue. Ten hours off duty gives drivers
enough time for 7-8 hours of sleep. In addition, adopting a non-
extendable 14-hour duty tour (reduced by one or more hours from the
pre-2003 rule) will also limit the accumulation of fatigue. The off-
duty and duty-tour provisions collectively help ensure that drivers can
maintain a 24-hour cycle. Comments also support the notion that the
restart helps drivers stay on a 24-hour circadian cycle. In addition,
today's rule moves drivers from an 18-to 21-hour driving time/off-duty
cycle, which is far closer to a 24-cycle than previous rules achieved,
thereby reducing the severity of a backward rotating schedule,
resulting in less driver fatigue. Further, the revised sleeper-berth
requirement provided by this rulemaking also gives drivers the
opportunity to obtain 7-8 hours sleep. These provisions, together with
the 34-hour recovery period, are more than adequate to allow drivers to
return to baseline alertness levels.
This provision protects a majority of drivers because 78 percent of
driving time occurs between 6 a.m. and midnight [Campbell, K.L., &
Belzer, M.H. (2000), p. 115]. Specifically, the 10 hours off duty
coupled with the reduced, non-extendable 14-hour duty tour will provide
drivers the opportunity for sufficient recuperative rest on a daily
basis to drive and work the daily maximum limits allowed by today's
rule. Therefore, the recovery period serves as an added safety net to
protect drivers from instances when cumulative fatigue does occur over
a 7- or 8-day period.
Research concerning specific recovery periods is limited. Most
sleep researchers agree the ideal recovery time for cumulative sleep
loss would be an opportunity to obtain sleep during two uninterrupted
periods from midnight to 6 a.m. [Belenky, G., et al. (1998), p. 13;
Bonnet, M.H. (1994), p. 62].
The 2003 rule treats daytime and nighttime driving equally, both in
terms of hours permitted and required recovery time. While it is
recognized that daytime sleep obtained by night
[[Page 50024]]
drivers is not equivalent in quality to night sleep [Akerstedt, T.
(1997), p. 105] research concerning specific recovery requirements,
particularly for night drivers, is limited. Working/driving during the
night, especially midnight to 6 a.m., has the combined effect of
affording poorer quality sleep (daytime sleep) and requiring the driver
to work and drive during the time when the physiological drive for
sleep is strongest. In preparation for the 2000 NPRM, FHWA convened a
panel of experts to advise the Agency on science associated with
various aspects of the proposed hours of service regulation.
With respect to night driving, the Expert Panel, after reviewing
the relevant literature, came to the conclusion that accident risk is
substantially higher during nighttime hours, independent of the length
of time on the job, and this elevated risk cannot be ignored. The
expert panel also determined that driving between the hours of midnight
and 6:00 a.m. is associated with as much as a 4-fold or more increase
in fatigue-related crashes, because our body clock is ``set'' to wake
us up in the morning and to send us to sleep at night. The panel
concluded that even when adequate sleep time is available during the
day, the time actually spent sleeping is less than at night. Shift work
and night work are associated with acquisition of less sleep, even when
night work is permanent. The panel surmised that this is caused by
disrupting effects of circadian cycles and that sleep obtained is not
only reduced in length, but also poorer in quality.
The science supports the notion that drivers should be provided
recovery periods after a sustained period of daily work to compensate
for any build-up of cumulative fatigue or sleep deprivation [Belenky,
G., et al. (1998), p. 12]. There is, however, no scientific basis for
concluding that every driver, or even every nighttime driver, is sleep
deprived. As mentioned, FMCSA has determined that the 34-hour recovery
period gives the majority of drivers the opportunity to obtain two
uninterrupted nights of 8 hours of recovery sleep.
However, other sleep researchers indicate that recovery to baseline
performance levels can be achieved with as little as 24 hours recovery
time [Alluisi, E.A. (1972), p. 199; Feyer, A.M., et al. (1997), pp.
541-553; O'Neill, T.R., et al. (1999), p. 2]. Smiley and Heslegrave
[Smiley, A., & Heslegrave, R. (1997), p. 8], in their literature review
regarding 36-hour recovery, identified a study that suggests one day
off is insufficient for night workers to pay off the accumulated sleep
debt from 5 days of work.
IIHS and Elisa Braver cited Park et al. (2005), as a study that
purportedly showed that 34-hour restart is an insufficient period for
recovery. The Park study is an analysis of pre-existing crash and non-
crash data representing an estimated 16 million vehicle miles of
travel. The study reported, in part, that there is some evidence,
although not persuasive, that there may be risk increases associated
with significant off-duty time, in some cases in the range of 24-48
hours. The study suggests that ``restart'' programs should be
approached with caution. Two sets of models were estimated with the
data. Model 1 was developed to assess the effect of driving time which
is divided into 10, one-hour periods with the first hour serving as the
baseline. The second model retained driving time and added as
covariates 43 driving schedules manually derived and developed by
cluster analysis. The most significant deficiency in the study was that
there were a number of HOS rule changes in 2003 that make the data not
applicable. First, the off-duty time has increased from 8 to 10 hours
and the on-duty time went from 15 plus hours per day to only 14 hours
per day. Both of these changes were intended to reduce any cumulative
fatigue that might result. Second, the study and particularly the
models used could have been significantly improved if the study had
undergone a peer review process. Lastly, the authors concluded that
``there is some evidence, although it is far from persuasive, that
there may be risk increases associated with significant off-duty time,
in some cases in the range of 24-48 hours'' [Park, S-W., et al. (2005),
p. 16]. The Agency has examined the study, and like its authors, has
concluded that the findings are not persuasive that a shorter recovery
period presents greater risk to CMV safety.
Additionally, IIHS cited the Wylie [Wylie, C.D., et al. (1997)]
study as stating that 36-hour recovery was an insufficient period to
``zero out'' any cumulative fatigue. This study was also based on the
pre-2003 rule--drivers operating under the new rule should be less
susceptible to cumulative fatigue. The Wylie study was a small
demonstration study of a methodology that could be used to evaluate
drivers' recovery periods. Twenty-five drivers in small groups (4-5
drivers each) were used to evaluate different recovery periods (12, 36,
and 48 hours) and driving time. None of the recovery periods examined
were found to be of sufficient length for driver recovery. The study
concluded that the small subject sample limited the ability to make
reliable estimates of observed effects [Wylie, C.D. (1997), p. 27].
Given the authors' conclusion, the Agency has not relied upon the Wylie
study to evaluate the adequacy of the 34-hour recovery period.
As explained earlier, few studies address the effect of recovery
periods between work periods spanning multiple days, such as a workweek
[O'Neill, T.R., et al. (1999), p. 2; Wylie, C.D., et al. (1997), p. 27;
Smiley, A., & Heslegrave, R. (1997), p. 14]. After reviewing the
studies relevant to the 34-hour recovery period, as cited in the 2003
rule and those submitted by commenters to the 2005 NPRM, the Agency has
determined that current scientific evidence is limited. Therefore,
changes in HOS regulations must, in addition to considering the
relevant science and research, be accompanied by sound regulatory
evaluation that encompasses all relevant issues, including public
interest, cost, and public safety.
The Agency considered implementing a restart period of 44 hours.
This would give more drivers, specifically nighttime drivers, an
opportunity to be off duty for two nighttime periods between midnight
and 6 a.m. However, it would also encourage drivers to operate on a
rotating shift, not to mention shifting more drivers to day time,
thereby increasing traffic during the day. A forward-rotating schedule
would result in a driving schedule that would cause a driver to begin
working at a later time of day than the previously used weekly
schedule. Therefore, toward the end of each work week, the driver would
begin work later and later each day, ultimately shifting the driving
and on-duty time into the nighttime hours. Consequently, the added
recovery hours would have a negative impact on a driver's circadian
cycle.
The Agency attempted to determine whether the added hours of
recovery, through the use of a 44-hour recovery period, created a net
benefit in reducing fatigue compared to the potential negative impact
on circadian rhythm of establishing a rotating schedule. The Agency has
determined there is no conclusive scientific data to guide it in
determining which factor (recovery time vs. circadian disruption) is
more effective in alleviating fatigue. In sum, in deciding to adopt a
34-hour recovery period, the Agency considered that compliance with a
34-hour recovery period results in a CMV driver restarting work at
approximately the same time of day as his or her prior shift. The 34-
hour recovery period also avoids the shifting of daytime to nighttime
schedules,
[[Page 50025]]
which research indicates can disturb the circadian rhythm and decrease
alertness.
Public Comments
In the 2005 NPRM, the 34-hour recovery period received support from
more comment letters than any other provision (591 approved versus 109
disapproved). The commenters said that the 34-hour recovery period
makes scheduling much easier than working with the old rolling weekly
limits. Comments also indicated that 34 hours off duty are long enough
to allow recovery (111 of 130 comment letters that addressed the
issue). According to a 2004 survey, among 31 fleets that responded, the
34-hour restart is the most utilized feature of the 2003 rule. The
survey, titled ``A Survey of Private Fleets on their Use of Three New
``Hours of Service Features','' conducted by Stephen V. Burks of the
University of Minnesota, found that ``most widely used among survey
respondents is the 34-hour Restart, which is employed on average of 61
percent of the runs of firms in the sample'' [Burks, S.V. (2004), p.
2]. Additionally, driver surveys have shown time to spend at home and
with family was identified as a major priority [Belenky, G., et al.
(1998), p. 41].
Public Safety and Operational Concerns
As mentioned earlier in this section, many comments to the 2000
NPRM suggested that by requiring all drivers to take two midnight to 6
a.m. recovery periods, FMCSA would be increasing the number of heavy
vehicles operating in daytime traffic. The commenters stated that this
would create greater hazards to public safety. While ideally all CMV
drivers can benefit from obtaining two nights of sleep, FMCSA continues
to believe, as stated in the 2003 rule (68 FR 22477), that restricting
nighttime driving by mandating a midnight to 6 a.m. off-duty period for
all CMV drivers would have the unintended consequence of substantially
increasing the number of heavy vehicles in daytime traffic, creating
greater hazards for the average motorist simply because of the higher
density of vehicles.
The Agency also took into consideration that not all motor carrier
operations work on a ``fixed and recurring 7-day period,'' instead
having intense days of work followed by slack times, and that other
operations can be disrupted by weather. For example, one commenter
discussed how weather affects the logging transportation industry. The
commenter explained that a CMV driver might begin the workweek on
Monday, fully rested and work a full 14-hour day, which is interrupted
by a full day of rain (Tuesday). The commenter explained the 34-hour
recovery period allows the CMV driver to resume work on Wednesday and
be able to work in compliance with the regulations to accomplish the
work required during that work week. The Agency has decided the 34-hour
recovery gives motor carriers and drivers the option of restorative
rest during the times work is not available or is interrupted. Given
that the recovery provision can be taken at any time, it is a flexible
safety tool that can be used by drivers as an added restorative safety
measure.
Health
The 34-hour recovery provision has turned out to be one of the most
popular provisions of the 2003 rule among CMV drivers. Several carriers
indicated they now see drivers proactively scheduling extended off-duty
recovery periods into their workweek and returning after these extended
periods with ``positive attitudes and appearing rejuvenated,'' which
promotes improved driver health.
FMCSA examined the effect of the new rule on driver work hours by
comparing survey data obtained before and after the 2003 rule was
implemented. A detailed discussion of those results along with
confirming data from multiple carriers can be found in Section E''
Driver Health. These data show that CMV drivers are not working longer
hours as a result of the 2003 rule than they did under the pre-2003
rule. In addition, the Field Survey conducted by FMCSA showed that many
drivers are taking recovery periods considerably longer than the 34-
hour minimum. Fifty percent of the drivers were found to have taken 58-
plus hours of recovery time per week and 67 percent of drivers took 44
hours recovery time per week, as explained in Section I.1.
One of the reasons that the 34-hour recovery rule is so popular
among drivers is that it appears to provide for longer blocks of
consecutive hours away from work than the pre-2003 rule provided `` to
rest, to be with family, and to recover prior to the start of the next
work week. In a survey of its membership, OOIDA asked ``Do you get more
time at home under the new HOS regulation?'' Twenty percent of OOIDA
drivers responded ``yes''--that they were getting more time at home as
a result of the 2003 rule. A slightly higher percent (21 percent) of
long haul drivers responded that they were getting more time at home
compared to short-haul drivers (18 percent). The survey question's
wording did not allow for an examination of how many drivers may be
spending less time at home as a result of the 34-hour recovery. It
appears that for some drivers the 34-hour recovery period may allow
more time at home and provide for greater stabilization of family life.
The impact of these factors is difficult to quantify from a driver
health perspective, but an improved quality of life may lead to
improved health. Few research studies have been conducted that address
this particular issue. (See Combined Effects--Section J.11, for further
discussion.)
As explained earlier, the 34-hour recovery period provides the
potential opportunity for drivers to increase their weekly driving and
on-duty time. The National Institute of Occupational Safety and Health
(NIOSH) reviewed the relationship between long hours and worker health.
It generally concluded that long work hours are associated with poorer
health, increased injury rates, more illnesses, or increased mortality.
However, the NIOSH review of the literature on long work hours also
documented a significant lack of data on general health effects. NIOSH
raised doubts about the strength of its own conclusions, stating that
``research questions remain about the ways overtime and extended work
shifts influence health and safety.'' NIOSH did, however, examine three
studies that identified the relationship between long shifts, those
typically worked by a CMV driver, and health or performance. The
results are documented in Section E--Driver Health.
Research indicates that psychological factors do play a role in the
health of individuals, including CMV drivers. For example, CMV drivers
generally want the freedom to manage their workplace and schedule.
Given the shortage of CMV drivers, the ready availability of jobs, and
the high level of reported driver turnover, it is unlikely that any one
employer could require a driver consistently to work the maximum hourly
limits available in the 2003 rule or today's rule--unless a driver
chose to do so. In other words, working long hours is an individual
choice. A driver has the right to choose to work longer hours to earn
greater pay as long as he or she can operate a CMV safely. Survey data
presented and discussed earlier, from multiple sources, indicate that
contrary to the concerns expressed by some commenters, drivers are, in
fact, not driving more under the 2003 rule than they were under the
pre-2003 rule. Instead, the 34-hour recovery period is being used in a
positive way, i.e., more driver time with family and greater
operational flexibility and productivity.
[[Page 50026]]
Two studies in the NIOSH review found that compensation has a
strong effect on the perceived impact of long working hours. Siu and
Donald [Siu, O.L., & Donald, I. (1995), p. 30] and van der Hulst and
Geurts [van der Hulst, M., & Geurts, S. (2001), p. 227] suggested that
compensation may reduce the adverse effects of long work hours. The Siu
and Donald study [p. 48] reported a relationship between perceived
health status and overtime pay. Men from Hong Kong who received no
payment for overtime work had more health complaints than men who
received payment for overtime work hours. In addition, the van der
Hulst and Geurts study [p. 227] examined the relationship between
reward and long working hours in Dutch postal workers. This study also
showed that if workers are compensated, they are able to work longer
hours without negative consequences to their psychological health [Id.,
p. 237].
Few studies have examined how the number of hours worked per week,
shift work, shift length, the degree of control over one's work
schedule, compensation for overtime, and other characteristics of work
schedules interact and relate to health and safety [Caruso, C.C., et
al. (2004), p. 30.] Van der Hulst, who also conducted a review of
research literature on long work hours, concluded ``that the evidence
regarding long work hours and poor health is inconclusive because many
of the studies reviewed did not control for potential confounders. Due
to the gaps in the current evidence and the methodological shortcomings
of the studies in the review, further research is needed'' [van der
Hulst, M. (2003), p. 171].
There is no conclusive research showing that long hours alone are
associated with poor health, especially when taking into account
individual choice, compensation, and degree of control over one's work
schedule. Also, given the results of FMCSA's 2005 survey of driver
hours, it is unlikely that the current HOS rules increase the overall
number of hours a driver actually works. In short, given current
knowledge, there is no clear evidence that the work hours allowed by
today's rule will have any impact on driver health.
Limits on the Use of the 34-Hour Restart Period
During the implementation of the 2003 final rule, several
enforcement issues were identified and subsequently addressed through
an Agency policy directive dated November 25, 2003. The policy memo
provides guidance to roadside law enforcement officials on how to
implement the 34-hour restart provision, when drivers have exceeded the
60/70 hour rule. Regulatory officials, motor carriers and CMV drivers
complained that the interpretive guidance provided by FMCSA was not
consistent with the wording of the regulation.
After reviewing the comments and considering all enforcement
remedies available to Federal and State regulatory agencies, FMCSA has
decided that if a driver has exceeded the 60/70-hour rule, the driver
does not have to come into compliance with the 60/70-rule before
utilizing the 34-hour recovery period. However, the driver could be
subject to appropriate penalty provision as provided by 49 CFR Part 386
for violating the provisions of 49 CFR 395.3(b). FMCSA is considering
additional enforcement remedies in its EOBR rulemaking for both motor
carriers and CMV drivers that violate the provisions of 49 CFR
395.3(b).
Questions also arose concerning the appropriate amount of time a
driver must be placed Out-Of-Service (OOS) prior to being allowed to
drive again for exceeding the 60/70-hour rule in 7/8 days. The length
of an OOS period required to bring a driver back into compliance is
currently determined based on the number of hours the driver is in
excess of the rule. The Agency did change this practice with the
implementation of the 2003 final rule.
In this rulemaking FMCSA has decided the driver should be placed
OOS for the minimum amount of time necessary to bring the driver into
compliance with the provisions of Sec. 395.3(b), or be allowed to take
a 34-hour recovery period, whichever is less. As explained earlier in
this preamble, a 34-hour recovery period will allow a driver ample
opportunity to obtain sufficient rest, even if the driver has exceeded
the 60 or 70 hour limits.
Conclusion
In adopting a 34-hour recovery period, FMCSA has taken into account
the weekly accumulation of driving and on-duty time allowed during each
7- and 8-day period, the adequacy of the 34-hour recovery, the cost/
benefit ratio, the overwhelming support of the 34-hour recovery by the
transportation industry, including motor carriers and drivers, the
long-term effect on driver health, and the overall safety aspects of
retaining this provision.
FMCSA is charged with creating minimum safety standards for CMV
drivers under the Motor Carrier Safety Act of 1984 [49 U.S.C.
31136(a)]. The Agency is also required to consider the economic costs
and benefits that the rule would impose on the trucking industry and
the public [49 U.S.C. 31136(c)(2)(A) and 49 U.S.C. 31502(d)]. As a
regulatory Agency, FMCSA must sift through general, and often
conflicting, scientific data and attempt to apply it ``in the real
world.''
When considering previous studies cited in the 2003 rule in support
of the 34-hour recovery period and subsequent studies cited in comments
to the 2005 NPRM, the Agency determined that, in light of the
scientific evidence, FMCSA's best judgment is that 34 hours provides a
minimum amount of time for a majority of drivers to recover from any
cumulative fatigue that might occur during any multi-day duty period.
J. 9. Sleeper-Berth Use
Under the 2003 rule, drivers are permitted to accumulate the
minimum off-duty period of ten consecutive hours four separate ways:
(1) A minimum of 10 consecutive hours off duty; (2) A minimum of 10
consecutive hours in a sleeper berth; (3) By combining consecutive
hours in the sleeper berth and off-duty time that total 10 hours; or
(4) By combining two separate sleeper berth rest periods totaling at
least 10 hours, provided that neither period is less than 2 hours
(split sleeper berth exception).
Although FMCSA has found that drivers need 10 consecutive hours of
off-duty time to obtain the necessary 7 to 8 hours of restorative sleep
per day, the split sleeper berth exception in the 2003 rule allows a
driver to accumulate his or her sleep in two separate periods that
totaled at least 10 hours.
Splitting sleep into short periods is a concern. One study, ``The
Effects of Sleep Deprivation on Performance During Continuous Combat
Operations'' [Belenky, G., et al. (1994), p. 129)], found that ``Brief
fragmented sleep has little recuperative value and is similar to total
sleep deprivation in its effects on performance.'' While this study was
conducted on soldiers attempting to sleep in busy, noisy command
centers, it may still be relevant in some cases when discussing sleeper
berth rest, depending upon the environment in which the vehicle is
parked and the physical condition of the sleeper berth or truck-tractor
cab.
Sleeping in a sleeper berth has been studied as it relates to truck
fatalities. A study by the Insurance Institute for Highway Safety
[Hertz, R.P. (1988), p. 7] found that splitting sleep into two sleeper
berth periods without having 8 consecutive hours in the sleeper berth
``increased the risk of fatality over twofold.'' Hertz also found that
split
[[Page 50027]]
sleeper berth use increased fatality risk ``in all analyses except
those limited to urban crashes and local pick-up and delivery
crashes.'' [Id., p. 9]
In a 1996 safety study, the NTSB found that the duration of the
most recent sleep period in the 24 hours prior was the most important
factor for predicting a fatigue-related crash [Id., p. 51]. The NTSB
also noted that the hours of service regulations at the time (8 hours
off-duty) did ``not provide the opportunity to obtain an adequate
amount of sleep'' and recommended that the use of split sleeper berth
time be eliminated [Id.]
FMCSA has determined that the available science and literature do
not support the continued use of the current split sleeper berth
provision. Surveys indicate that only a small percentage of drivers
split their sleeper berth time to obtain the necessary off-duty time.
An OOIDA survey conducted in 2004 indicates that their members use a
split sleeper berth 13 percent of available workdays each month. A
survey of private motor carriers [Burks, S.V. (2004), pp. 3-4]
indicates that split sleeper berth use in the private fleets is on
average about twice as high as the OOIDA number. However, Burks pointed
out that of the private firms that use sleeper berths ``half the sample
utilizes the [split] [s]leeper berth 2% of the time or less'' [Id., p.
3].
The split sleeper berth exception is also problematic from a driver
health standpoint. There is a growing body of research demonstrating
that sleep periods of 4 hours, or less, can result in a number of
adverse physiologic medical symptoms or conditions that result from
having a specific disease, including reduced glucose tolerance,
increased blood pressure, activation of the sympathetic nervous system,
reduced leptin levels, and increased inflammatory markers [Alvarez,
G.G., & Ayas, N.T. (2004), p. 59]. Consistent with these studies,
epidemiologic research demonstrates that short sleep duration is
modestly associated with symptomatic diabetes, cardiovascular disease,
and mortality [Id.]. Given the uncertainty with regard to combining two
sleep periods these studies suggest that drivers need one period of
sleep that is between 7 to 8 consecutive hours daily in order to
maintain a healthy lifestyle.
Comments
Approval of the Split Sleeper-Berth Exception. The FMCSA asked
commenters to address the fundamental question of whether the Agency
should eliminate the split sleeper-berth exception and require drivers
to take 10 consecutive hours off duty (either in a sleeper berth or in
combination with off-duty time).
A total of 130 commenters expressed general approval of the split
sleeper-berth provision. Of these, four were trucking associations
(ATA, OOIDA, Associated Petroleum Carriers, and Corporate
Transportation Coalition), 42 were carriers, 80 were drivers, and four
were private citizens. Commenters stated that the provision allowed
drivers to take naps when needed, and to avoid traffic congestion.
Maverick Transportation, C.R. England, OOIDA, and Werner stated
that the split sleeper-berth exception is the only way a driver can
take a needed nap without being penalized. Werner noted that over 80
percent of its drivers use the sleeper berth on a regular basis. C.R.
England described a study of split sleeping time which indicates that
total sleep time per 24 hours is the most important determinant of
performance, and that sleep can be split into an anchor period of at
least 6 hours sleep and another period of 2 hours with a combined
effect roughly equivalent to the performance and alertness that is
obtained from a continuous 8 hour sleep period. The commenters
concluded that the sleeper berth, when used properly, did not reduce
drivers' ability to obtain adequate restorative sleep.
Disapproval of the Split Sleeper-Berth Exception. Almost as many
commenters (a total of 112), however, expressed general disapproval of
the split sleeper-berth exception. These included AHAS, Public Citizen,
18 carriers, 86 drivers, the Georgia Department of Motor Vehicle
Safety, and four others. The reasons for disapproval varied. Several
commenters noted that the rule was an invitation for cheating, while
others stated that split sleeper berth periods do not provide enough
rest.Public Citizen strongly opposed the split sleeper-berth provision
and stated that the exception allowed solo drivers to divide their rest
time any way they wanted, despite FMCSA's repeated findings that
drivers need 8 hours of uninterrupted sleep. They noted that the
increase in minimum off-duty time in the current HOS rule from 8 to 10
hours was based on FMCSA's assertion that a driver with only 8 hours of
off-duty time generally obtained only 5 hours of sleep, and cited
FMCSA's statements that studies point specifically to increased crash
risk after fewer than nine hours of off-duty time. They noted that
FMCSA has acknowledged that research from all transportation modes
suggested a need for off-duty periods of 10 to 16 hours to ensure the
needed block of sleep. They stated that studies are unanimous that
drivers get both less sleep and lower quality sleep when it is taken in
two separate sleeper-berth or other rest periods. Public Citizen cited
a study suggesting drivers usually got no sleep during logged sleeper-
berth periods.
Public Citizen noted that a 1997 OOIDA study showed that nearly 75
percent of drivers took their off-duty time in a single block. The
study showed that those who split their sleeper-berth breaks on average
took two 4-hour breaks. Public Citizen recommended that solo drivers
should take at least 10 consecutive hours off in a single block of
time, regardless of where the time was spent.
The Minnesota Trucking Association recommended that the split
sleeper-berth option be changed to reduce the minimum time block to 1
hour, and to allow up to three periods for the calculation of the total
split sleeper-berth time.
Minimum Necessary Length of Split-Sleeper-berth Periods. The Agency
requested information on the minimum time in each of two split-sleeper-
berth periods necessary to provide restorative sleep. Figure 9 provides
the breakdown of responses to FMCSA's question on minimum sleeper-berth
periods.
Figure 9.--Commenters: Suggested Minimum Sleeper Berth Period
------------------------------------------------------------------------
Minimum time Carriers Drivers Other
------------------------------------------------------------------------
< 2 hours......................... 11 30 1
2-3 hours........................ 3 11
3-4 hours........................ 2 2
4-5 hours........................ 5 7 1
5-6 hours........................ ......... 6
6-7 hours........................ ......... 1
7-8 hours........................ 1 4 1 (NTSB)
------------------------------------------------------------------------
Alertness Solutions reported research showing that obtaining 2
hours less sleep than needed (for an average adult this equates to
about 6 hours of sleep) produces a reduction in performance and
alertness. The data showed that obtaining a total of 8 hours of sleep
per 24-hour period is critical. However, sleep can be split into an
``anchor period'' of at least 6 hours of sleep and a period of 2 hours
of sleep at another time with a combined effect of performance and
alertness that is roughly equivalent to that obtained from a continuous
8 hour sleep period. Rosekind of Alertness Solutions concluded that
translating these scientific results into operational practice would
suggest that an ``anchor sleep opportunity'' of 6.5 hours and another
sleep opportunity of 2 hours would likely provide the minimum
[[Page 50028]]
number of sleep hours needed to maintain a performance level equivalent
to one 8-hour sleep period. He said no data indicate whether the order
of the two split sleep periods would have a significant effect. He also
noted that a sleeper berth provides significant flexibility and
proximity that should be regarded when determining the role and
opportunity for the use of split sleep. Although there could obviously
be a variety of combinations that might be considered for split sleep,
Rosekind concluded that two factors are critical. First, at least one
sleep period should provide sufficient opportunity for a minimum of 6
hours of sleep. Second, the combined total sleep obtained in the split
sleep periods should approximate 8 hours. AHAS, however, criticized
Rosekind for ignoring contradictory research that the split sleeper
berth periods do not provide sufficient rest and performance
restoration.
Several carriers reported on the sleeper-berth patterns of their
drivers. Yellow Roadway reported that 70 percent of its team drivers
split their sleeper-berth time into two 5-hour periods. C.R. England
said its teams split 5 and 5 or 6 and 4; its solo drivers usually split
6 and 4 or 7 and 3. Overnite reported that its teams split 5 and 5,
explaining that this pattern means that a driver never drives more than
5 hours at a time. Brink Farms and a driver also supported a 5-hour
minimum. Schneider said it limits solo drivers to 8 and 2 only and
believes the foundation period for solo drivers should be 8 hours.
Schneider provides its team drivers more flexibility.
Some carriers suggested mandatory split sleeper periods. Schneider
recommended that the total off-duty time be 9 hours, with an 8 and 1
split, citing a study that advised strategic naps of no more than 45
minutes. FedEx cited a study that showed that two periods totaling 7.4
hours resulted in performance equal to that obtained from a single 8.2
hour sleep period. J.B. Hunt also cited the same study to argue for an
anchor period of 6 hours, which could be combined with another 2 hours
of sleep and 2 hours off duty.
Most trucking associations endorsed a 5 and 5 split. ATA stated
that 5 and 5 has worked for team drivers and recommended continuation
of the 2003 rule. The Motor Freight Carriers Association (MFCA) also
supported 5 and 5 splits, and stated that company crash data indicate
that this does not result in an unsafe operating environment. MFCA
stated that a rule change that reduced team flexibility could have a
negative impact on driver safety, but provided no supporting data for
the assertion.
The California Highway Patrol (CHP) stated that the minimum
sleeper-berth period should be at least 5 hours; periods of less than 5
hours should count against the 14-hour day. CHP also asked that
``qualifying sleeper-berth period'' be defined.
The NTSB essentially rejected the split sleeper-berth option,
arguing that FMCSA should eliminate any provision that provides for a
daily sleep period of less than 8 continuous hours. The current split
exception allows for less than 8 hours of sleep in conditions that are
not optimal for sleeping, it said.
Impact of Increasing Minimum Split Time for Longer Periods. FMCSA
asked what the impact would be on driver health, the safe operation of
CMVs, and economic factors, if the Agency were to retain the split-
sleeper-berth provision, but require that one of the two periods be at
least 7, 8, or 9 hours in length. Four carriers, the California Highway
Patrol, and 25 drivers responded to this question. Eight commenters
(seven drivers and a carrier) stated that a single break of 7 hours
would be sufficient and no additional sleeper-berth period would be
needed. Seven commenters (six drivers and McLane Company) supported 7
hours plus another break, not necessarily in the berth. Four drivers
and McLane also argued that everyone is different and a single rule is
not appropriate.
The California Highway Patrol stated that requiring 7, 8, or 9
hours as a minimum for one of two qualifying sleeper-berth periods
would allow a driver to rest only 1, 2, or 3 hours (during the second
period) and then drive for an extended period of time. This might also
lead to disruption of the 24-hour cycle upon which the regulations are
based. Brink Farms argued that, for teams, an 8 and 2 split would do
more harm than good and supported a 5 and 5 split for teams. It also
supported allowing the second period to be out of the berth.
Yellow Roadway did not agree that 7 or more hours in the berth are
the equivalent of 10 hours off duty. The 10-hour period gives a driver
a chance for sleep and other personal time. A split with less than a
10-hour total would put the driver in a drive-sleep-drive-sleep
position that adds fatigue and diminishes ability.
McLane supported a combination of sleeper-berth and off-duty time
because few people sleep for 10 hours. FedEx Ground said the single 10-
hour period is rarely used; 2 and 8 and 3 and 7 are also rarely used.
Their drivers normally split 5 and 5 or 6 and 4. FedEx stated that it
had no evidence that the current rule has had negative effects on
fatigue or health and did not support requiring a single 10-hour
sleeper-berth period.
Frequency of Sleeper-Berth Use. In the NPRM, the Agency requested
information about how often split sleeper-berth periods are used to
obtain the required 10 or more hours of off-duty time. Sixty-five
commenters responded. Thirty commenters, including 7 carriers, 2 owner/
operators, and 21 drivers, said they only rarely or never used the
split sleeper berth option. Thirty-one commenters, including 27
drivers, said they used it often.
Among the carriers, B.R. Williams Trucking stated that less than 10
percent of its drivers use the exception. The reason the drivers give
is that it is too confusing. Tennessee Commercial Warehouse discourages
its contractors from using the exception, although about a quarter do.
J.B. Hunt stated that a survey of randomly selected over-the-road
driver logs showed that 14 percent of the time drivers use the
exception. Schneider stated that only 0.4 percent of its drivers used
the exception routinely. International Paper cited research presented
at a Transportation Research Board conference in January 2005
indicating that 26 percent of drivers use the exception.
OOIDA noted that the exception is the least used feature of the
2003 rule among respondents to its survey. About 55 percent of drivers
reported never using it, and 75 percent of drivers used it from zero to
four times in June 2004.
In contrast, Maverick stated that 70 percent of its drivers use the
exception. The Georgia Department of Motor Vehicle Safety stated that
its inspections and observations indicate that use of the exception is
very common.
Health and Safety Impacts of Eliminating the Sleeper-Berth
Exception. Four carriers, ATA, 22 drivers, and OOIDA commented on the
health and safety impacts of eliminating the exception. Eighteen
drivers stated that eliminating the exception would force drivers to
drive when tired.
Although OOIDA noted that the split sleeper berth exception is the
least used feature of the 2003 rule, it is ``appreciated'' by those who
use it. They include drivers who need to rest, but otherwise face
pressure not to take short breaks that decrease their available on-duty
and driving time. It is the only flexibility in the rule available to
drivers who absolutely need to rest. The sleeper berth also serves
drivers whose runs are of a certain length or whose pick-up or drop-off
times are arranged in a way that permits a continuous two-hour break.
[[Page 50029]]
Team drivers also find the sleeper-berth exception useful.
Yellow Roadway stated that the exception gives drivers flexibility
to divide driving time and take breaks when needed and where they
choose. Reducing team drivers' control of their work and rest
opportunities could have a negative impact on driver health, safety,
and business operations.
Economic Impact of Eliminating Split Sleeper-Berth Exception. Five
drivers and five carriers commented on this issue. Schneider stated
that only six percent of teams use the exception with any regularity.
However, elimination of this option within Schneider's teaming
operations would impact the organization by jeopardizing $250 million
in business opportunities with customers requesting team service.
Werner stated customer scheduling and delivery requirements are
such that regular hours are impossible. In addition to the limited
availability of motels with truck parking, there is a significant cost
to drivers staying in motels and the inconvenience factor of
maneuvering a large truck through urban or suburban areas to locate a
motel. If the sleeper berth exception were not available, there would
likely be a further increase in the truck parking problem, congestion,
and driver turnover.
McLane stated that elimination of the exception would virtually
eliminate use of sleeper-berth by all but cross-country long-haul
drivers. McLane's operating costs would significantly increase, due to
the need to hire additional drivers and equipment, while the overall
earnings for existing drivers would be reduced.
Quality Transport stated that eliminating the sleeper berth
exception would largely defeat the purpose of team driving. If the
teams cannot use the sleeper-berth rule, then they have no option but
to show on-duty time for any time spent not driving. This would be a
huge economic loss to companies using team operations, as it would
basically do away with the benefit of running as a team. The loss would
affect income for teams, plus income for the company they are leased to
or drive for. It would affect the current national market by curbing
deliverability of many products.
A driver also believed that the effect of eliminating the exception
would be to eliminate team operations. One driver said he would have to
stop driving over-the-road. Three stated that it would affect drivers
who use it to avoid traffic and shipper delays. One carrier simply
stated that it would decrease efficiency.
However, another driver saw a positive effect in eliminating an
opportunity for shippers, carriers, and receivers to use the exception
to pressure drivers to extend their work day. One said it would not
change anything, but would eliminate a lot of logbook fines.
Impact of Not Allowing a Single Sleeper-Berth Period to Extend the
Duty Period. FMCSA asked commenters to provide information about how
prohibiting the extension of the 14-hour tour of duty through the use
of a single sleeper-berth period affects driver health, safe
operations, and economic factors.
Numerous commenters addressed this issue. Nineteen drivers, two
carriers, a consulting group, OOIDA, and the California Highway Patrol
responded to the question about the health and safety impacts.
The Georgia Department of Motor Vehicle Safety described the
problem created by the current rule. An officer who encounters a driver
with a single sleeper period in the current tour of duty must either
predict the driver's future actions, or question the driver, and make a
judgment call about the driver's status.
The California Highway Patrol addressed the negative impact of
extending a driver's work day with only one sleeper-berth period,
stating that it effectively circumvents the intent of the regulation
and changes the driver's 24-hour cycle. It would allow drivers to
operate CMVs long after the completion of the intended 14-hour work
period. The Daecher Consulting Group also noted that allowing the
extension would permit a slippage or rotation of the duty day.
OOIDA described the requirement that both periods be in the sleeper
berth, even if the driver is at home, as ``absurd.'' They stated that
there is no justification for the requirement and are not aware of any
study that indicates that sleeping in a sleeper berth is better than a
bed. OOIDA recommended that the driver be able to replace the second
period with 10 hours off. This would allow the driver the flexibility
to restart the next day's schedule without having to relate back to the
first sleeper period. UPS supported the OOIDA position.
Combining Sleeper-Berth Periods With Off-Duty Periods To Calculate
Off-Duty Time. FMCSA asked whether the rule should allow sleeper-berth
periods to be combined with off-duty periods when calculating a
continuous off-duty period. The Agency also asked whether a sleeper-
berth period that is part of a period of 10 or more consecutive hours
off duty should be combinable with a later sleeper-berth period as part
of a split sleeper-berth calculation.
Support for combining sleeper-berth and off-duty time came from 141
commenters, including ATA, Minnesota Trucking Association, the National
Association of Small Trucking Companies, 41 carriers (including UPS,
FedEx, J.B. Hunt, Con Way, and Werner) and 94 drivers. Three drivers
were opposed.
The California Highway Patrol recommended that a driver who
combines a last sleeper-berth period with 10 hours off duty not be
penalized for resting at home or be forced to sleep in the truck.
However, if sleeper berth and off-duty time are combined, this same
sleeper-berth period should not be used in combination with a
subsequent sleeper-berth period. CHP recommended definitions of
``qualifying sleeper-berth period'' and ``subsequent sleeper-berth
period.''
The Georgia Department of Motor Vehicle Safety stated that a full
10-hour period of sleeper-berth time should not be combinable with a
shorter period of time.
ATA submitted an extensive argument in favor of amendments to the
split sleeper-berth provisions. ATA used four hypothetical schedules to
illustrate its argument, with three of the schedules in compliance with
the 2003 rule, and one not in compliance. ATA claimed its hypothetical
schedules demonstrated that, despite FMCSA's statement that drivers are
free to take naps or other rest breaks, the rule is a strong
disincentive to doing so if time in the sleeper berth results in lost
work time.
ATA also argued that the rule creates uncertainty for logbook
inspectors. Whether an extended work period is legal or illegal depends
on the intentions and subsequent actions of the driver, neither of
which can be known to the enforcement officer at the time of a logbook
check.
Based on its analysis, ATA recommended, and provided an extensive
discussion of the benefits of, detailed amendments to 49 CFR
395.1(g)(1)(iii) and 395.3(a)(2) and the addition of a new exception
specifying the following:
A property-carrying driver is exempt from the requirements of
Sec. 395.3(a)(2), and may extend the 14-hour limit in the event
that the driver has one sleeper-berth period with a minimum duration
of 2 hours, provided that the driver does not exceed 14 cumulative
hours of work or 11 hours of driving, and that the on-duty time is
followed by an off-duty time of at least 10 consecutive hours.
The American Bakers Association stated the inability to combine
off-duty
[[Page 50030]]
and sleeper-berth time ``must have been an oversight,'' arguing that it
made no sense for operators to be tying up equipment on the lot in the
sleeper berth when they want to go home and go to bed.
Some carriers supported the ATA position. Others made their own
recommendations for changes. UPS proposed permitting drivers to extend
the 14-hour on-duty window to account for breaks of at least 2 hours
taken in a sleeper berth when they are combined with 10 hours of off-
duty time immediately following the shift. UPS also proposed that
drivers be permitted to extend the 14-hour on-duty window to account
for sleeper-berth periods of at least 2 hours when they are combined
with a subsequent sleeper-berth period of any length, if it is
immediately followed by at least 10 hours of off-duty time. Both FedEx
Ground and Werner recommended strongly that drivers be able to finish
their 10 hours at home if they have a previously qualifying sleeper-
berth period. J.B. Hunt concurred and recommended that this be allowed
for other sleeping accommodations as well. It noted that an FMCSA
enforcement bulletin allowed this, but many jurisdictions refused to
implement the bulletin because it directly contradicted the plain
language of the regulation.
FMCSA Response
Primary Sleep Period. Although the comments to the docket are
closely divided over how to address the split sleeper berth exception,
the majority of studies and science clearly demonstrate that drivers
need to have at least one primary sleep period of 7 to 8 consecutive
hours.
A study of chronic sleep restriction [Maislin, G., et al. (2001)]
showed that it is possible for a person to avoid physiological
sleepiness or performance deficits on less than 7 hours of sleep;
however, the subjects in the study were obtaining their primary sleep
period at night and were supplementing their sleep with longer naps
later in the day. Maislin et al. found that subjects who slept for 6.2
hours at night combined with a nap of 1.2 hours had lower levels of
sleepiness and higher levels of performance, compared to subjects who
slept shorter periods without naps. While 6 hours of sleep at night
with a nap may be the minimum needed to maintain an adequate
performance level, it is unrealistic to think that the Agency can
regulate what time of day a driver goes off duty or sleeps in a sleeper
berth.
Consequently, today's final rule modifies provisions for the use of
sleeper berth time. The Agency will continue to allow drivers to use
the sleeper berth to obtain their required off-duty time; however,
drivers using this option will be required to obtain one primary sleep
period of at least 8 consecutive hours. Unlike drivers who have to
commute to and from work and perform personal tasks after going off
duty, sleeper-berth drivers do not need 10 consecutive hours off duty
in order to have an opportunity for 7-8 consecutive hours of sleep.
Because their bedroom travels with them, sleeper-berth drivers can
obtain adequate sleep in an 8-hour period. These drivers will also be
required to take another separate two consecutive hours of off-duty
time, sleeper berth time, or a combination of both. These additional
hours will allow time for naps and other breaks, and will prevent
drivers from operating on a 19-hour schedule (8 hours in the sleeper
berth followed by 11 hours of driving) that would seriously compromise
their circadian rhythm.
For example, a driver who takes 9 consecutive hours in the sleeper
berth would later have to take at least 2 consecutive hours of sleeper-
berth or off-duty time or a combination thereof to meet the minimum
requirements. Since the driver did not obtain a single period of 10
consecutive hours of off-duty or sleeper berth time, the driver is
required to make up the balance of his or her off-duty or sleeper berth
time later in the duty period.
These requirements will ensure that drivers using the sleeper berth
to obtain the minimum off-duty time have at least one primary sleep
period of a sufficient length to provide restorative benefits. The
second period will allow a driver to have time for a nap or rest break
or provide an opportunity to attend to personal matters. The
opportunity to take a nap later in the day is an important benefit,
especially since drivers taking advantage of the sleeper berth
provision may be operating on an irregular/rotating schedule, getting
out of phase with their natural circadian rhythm.
Overwhelmingly, the research literature supports the need for most
people to obtain 7 to 8 hours of sleep per day. A study of driver
fatigue [Wylie, C.D., et al. (1996), p. ES-10] found that the average
amount of ``ideal'' sleep time reported by participating drivers was
7.2 hours. The NTSB [NTSB (1996), p. 26] found that drivers in non-
fatigue related crashes had averaged 8 hours of sleep during their last
sleep period prior to the crash versus drivers involved in fatigue-
related crashes whose prior night sleep averaged only 5.5 hours. A
study of soldier performance [Belenky, G.L., et al. (1987), p. 1-10]
noted that ``the vast majority of adults required 6-8 hours of sleep
each night to maintain adequate, normal levels of daytime arousal.''
Belenky et al., further noted that a person getting ``six to eight
hours sleep each night will maintain cognitive performance'' [Id., p.
1-17].
Research supports the benefits of sleeping at night, rather than
during the day, but the needs of the U.S. economy and the operational
realities of the motor carrier industry make it is impossible for FMCSA
to ensure that drivers obtain all of their rest during nighttime hours.
Given this, and the results of earlier studies that suggest sleep
obtained in a sleeper berth is not as restorative as sleep obtained in
a bed, today's rule will require drivers using the sleeper berth
exception to obtain at least one primary sleep period of 8 consecutive
hours in the sleeper berth. This provision maintains some of the
flexibility provided by the 2003 rule, and ensures that drivers have
the opportunity for 7 to 8 consecutive hours of uninterrupted sleep.
The economic impact of this provision will be the greatest in the
long-haul sector of the industry; however, the ``Commercial Motor
Vehicle Driver Fatigue, Alertness, and Countermeasures Survey''
[Abrams, C., et al. (1997), p. 12] found that the majority of drivers
using the split sleeper berth exception already average 6 to 7 hours in
the sleeper berth. In addition, the 2005 FMCSA Field Survey data show
that of the 2,928 sleeper berth periods reviewed, 68 percent exceeded 6
hours and 52.6 percent exceeded 8 hours, so the overall impact on the
industry should be relatively small [FMCSA Field Survey Report (2005),
p. 2].
Rest Breaks. The requirement for an additional 2 consecutive hours
of off-duty or sleeper-berth time for drivers using the sleeper berth
provides a number of additional benefits. It ensures that all drivers
(those using a sleeper berth, and those not using a sleeper berth) will
have the same amount of time to drive and work every week. It also
provides the opportunity for a sleeper berth driver to eat meals,
bathe, exercise, and conduct other personal activities. Most
importantly, the 2 consecutive hours provide the driver with the
opportunity to nap, if and when needed.
Rest breaks, and especially naps, are an important tool in
combating fatigue and the FMCSA encourages their use. As noted by Wylie
[Wylie, D. (1998), p. 13], ``[n]aps in trips with judged
[[Page 50031]]
drowsiness appeared to result in recovery effect, compared to the
relatively high levels of drowsiness seen in the hour prior to
napping.'' Research on napping indicates that while it does not reduce
accumulated fatigue, it does refresh a driver and improves performance
in the near term. In another study of military operations [Caldwell,
J.A., et al. (1997), pp. 2-5] the subjects performed better after
napping compared to resting without sleep. In addition to working as a
short-term countermeasure to fatigue experienced during working hours,
another study [Garbarino, S., et al. (2004), p. 1300] found that
napping ``before night work can be an effective countermeasure to
alertness [deterioration] and performance deterioration.''
The Agency recognizes that drivers who are able to get 7 to 8 hours
of sleep per day may not require additional sleep and it would be
unreasonable to require the driver to stay in the sleeper berth for an
additional two hours. For this reason, the FMCSA will permit drivers to
accumulate the additional two hours as sleeper berth time, off-duty
time, or a combination of both. Two hours are long enough to permit
time for a nap, as well as time to attend to personal matters. Studies
have found that naps do not have to be long to improve performance. A
study of working at night [Sallinen, M., et al. (1997), p. 25] found
that naps of less than one hour most influenced performance, and a
survey of train engineers found that 20 minute napping was effective
for enhancing alertness [Moore-Ede, M., et al. (1996), p.10].
Although this provision on the use of sleeper berths does reduce
the total flexibility provided in the 2003 rule, it provides motor
carriers and drivers with some operational flexibility while ensuring
that drivers are afforded the opportunity of at least one 8-hour sleep
period each 24 hours, with the additional benefit of providing the
option for a nap or break.
Enforcement. The prior split sleeper berth provision caused some
confusion in law enforcement and the motor carrier industry. The
question has been how to calculate split sleeper berth time, and how
split sleeper berth periods affect the calculation of the 14-hour duty
``window.''
The calculation of the driver's 11-hour driving limit and 14-hour
duty ``window'' will restart once a driver has at least 10 hours of
off-duty time, whether it is (1) 10 consecutive hours of sleeper berth
time; (2) 10 consecutive hours of off-duty time; or (3) a combination
of 10 consecutive hours of sleeper berth and off-duty time. Drivers
using sleeper berths have a fourth option to obtain the equivalent of
10 hours off duty by combining two separate periods of sleeper berth or
off-duty time that total at least 10 hours. When calculating off-duty
time for drivers using sleeper berths under this rule, only two
separate periods may be used and both must add up to at least 10 hours.
One period must be at least 8 consecutive hours of sleeper berth time.
The second period must be at least 2, but less than 10, consecutive
hours of sleeper berth time, off-duty time, or a combination of both.
For drivers using two separate periods of sleeper berth and off-
duty time, the calculation of the driver's 11-hour driving limit and
14-hour duty ``window'' will begin from the end of the first period
used in the calculation. This will provide a simplified method for
calculating a driver's on-duty and driving time and address some of the
enforcement concerns received in the comments.
For example, following 10 consecutive hours off-duty, a driver
begins driving at 5 a.m. At 10 a.m., the driver takes 2 consecutive
hours off-duty (1 hour of off-duty time followed by 1 hour of sleeper
berth time). At noon, the driver drives for another 5 hours. At 5 p.m.,
the driver goes into the sleeper berth for 8 consecutive hours. At 1
a.m. the driver begins driving again. In this example, the calculation
of the driver's on-duty and driving time begins at the end of the first
off-duty/sleeper berth period, or noon. Therefore, this driver has 5
hours of driving time available at 1 a.m. At no time will a driver have
a combination of more than 11 hours of driving time on either side of a
sleeper berth period or off-duty period that is less than 10 hours in
length.
The driver's 14-hour duty ``window'' is calculated differently from
the way it was calculated under the 2003 rule. As identified in a
petition filed by ATA on November 3, 2003, and numerous docket comments
on this subject, FMCSA will not count any sleeper berth period of at
least 8 but less than 10 consecutive hours toward the 14-hour limit
after coming on duty. The ATA petition requested that any sleeper berth
period of at least two consecutive hours be excluded from the
calculation of the 14-hour duty ``window,'' provided that the driver
took 10 consecutive hours off-duty either upon reaching his or her 14-
hour limit, or 11-hour driving limit. The Agency's response to that
request, and the comments provided to the docket, is to allow any
sleeper berth period of at least 8 but less than 10 consecutive hours
to be excluded from the calculation of the 14-hour duty ``window.''
This will ensure that drivers using a sleeper berth to obtain their
minimum off-duty time are not negatively impacted by having to take at
least one sleeper berth period of at least 8 consecutive hours, which
would normally count against their 14-hour duty ``window,'' leaving the
driver with only 6 hours of time to work and drive. Any period of less
than 8 consecutive hours in the sleeper berth will count toward
calculation of the 14-hour ``driving window.''
In the earlier example, the driver would have reached the 12th hour
of his or her 14-hour duty ``window'' at 5 p.m. when he or she went
into the sleeper berth for 8 consecutive hours. Because the driver has
10 hours of off-duty time (2 hour break, combined with 8 consecutive
hours in the sleeper berth), the calculation of the 14-hour duty
``window'' begins at the end of the 2-hour break (noon). However, when
the driver starts driving at 1 a.m., he or she would only be at the 5th
hour of his or her 14-hour duty ``window,'' because the 8 consecutive
hours in the sleeper berth are excluded from the calculation. The
Agency believes that this will simplify the calculation used by
enforcement officers during roadside inspections, as well as by drivers
as they calculate their daily on-duty and driving limits.
In the Agency's best judgment based on available data and comments,
this sleeper berth provision creates an optimal balance by providing
drivers with one 8-hour sleep period, combined with an additional
sleeper berth or off-duty period, while maintaining operational
flexibility so as not to impose an unreasonable burden on motor carrier
productivity.
J.10. Regulation of Short-Haul Operations
Motor carriers whose operations require the driver to return to
their work-reporting location every night and are conducted solely
within a 150 air-mile radius from their terminals are generally
considered short-haul operations. Short-haul drivers perform a variety
of non-driving tasks during the day, including receiving the day's
schedule, loading and unloading the vehicle, making deliveries, getting
in and out of the vehicle numerous times, lifting and carrying
packages, and engaging in customer relations. Because of the nature of
short-haul operations, smaller vehicles (i.e., less than 26,001 pounds)
tend to be favored for their maneuverability, which makes them ideal
for pick up and delivery in a local, or urban setting.
[[Page 50032]]
A review of the U.S. Census Bureau's Vehicle Inventory and Use
Survey (VIUS), 2002, shows that trucks weighing 26,000 pounds or less
make up about half of all registered trucks and represent about a
quarter of all truck miles traveled. Trucks weighing 26,000 pounds or
less accounted for only one-seventh of all trucks involved in non-fatal
crashes, and only one-tenth of all trucks involved in fatal crashes,
according to data found in the Motor Carrier Management Information
System (MCMIS) and the Fatality Analysis Reporting System (FARS).
Relative to their share of registered trucks and annual truck miles
traveled, trucks weighing 26,000 pounds or less are underrepresented in
fatal and non-fatal truck-involved crashes.
A study of the Impact of Local/Short Haul Operations on Driver
Fatigue by Richard Hanowski and others suggested ``fatigue may not be
the most critical issue'' in the safety of short-haul operations
[Hanowski, R. J., et al. (1998), p. 72]. Short-haul drivers who were
asked to describe the safety problems they faced ranked fatigue fifth,
below problems as obscure as the design of loading docks and freeway
on- and off-ramps. In explaining why short-haul operations did not
produce critical levels of fatigue, the drivers said that ``unlike
long-haul drivers, [they] typically work during daylight hours, have
work breaks that interrupt their driving, end their shift at their home
base, and sleep in their own beds at night'' [Id.]. Hanowski et al.
concluded that ``[p]erhaps, when it comes to fatigue, [local/short-
haul] drivers are more like workers of non-driving professions where
fatigue may not result from their work, as in long-haul, but may be
impacted by their personal lives (such as not getting enough sleep at
night)'' [Id. p. v]. While FMCSA cannot control drivers' off-duty
behavior, the 2003 HOS rule and today's final rule give local/short-
haul drivers two more hours off duty than the regulations in effect in
the late 1990s, when the Hanowski study was completed. If fatigue was
not critical at that time, it is even less likely to be a significant
threat today. Compared to long-haul drivers, local short-haul drivers
have a better opportunity to obtain the daily restorative rest needed
to maintain vigilance in an environment that provides quality sleep.
Historically, the Federal Motor Carrier Safety Regulations have
recognized differences between long-haul and short-haul operations.
FMCSA realizes that short-haul operations are involved in crashes, and
sometimes even fatal crashes, as evidenced by the crash data referenced
earlier. However, the representation of short-haul vehicles weighing
less than 26,001 pounds in large truck crashes is much lower than their
share of the total truck population and miles traveled. The regulatory
impact analysis (RIA) for the 2003 HOS rule bore this out, and
researchers estimated the costs of imposing that rule on short-haul
carriers would far exceed any safety benefits resulting from a
reduction in fatigue-related crashes. Conversely, the net benefits of
imposing those HOS rules on long-haul carriers were quite positive,
primarily due to a reduction in fatigue-related crashes by long-haul
drivers.
Today's HOS rule adopts two exemptions for short-haul drivers also
provided in the 2003 rule, though neither significantly improves the
regulatory cost/benefit ratio of short-haul operations. The first is
known as the ``100 air-mile exemption,'' and provides relief from a
paperwork burden for drivers who meet specific duty time requirements
(report to and leave from work within 12 consecutive hours) and operate
in a 100 air-mile radius of their work reporting location [49 CFR
395.1(e)]. Because drivers operating within a limited radius commonly
make frequent stops, deliveries, and pick-ups throughout the day, which
would normally require many entries on their records of duty status
(RODS), this provision exempts drivers from completing RODS, as long as
the motor carrier maintains a proper daily time record. The Interstate
Commerce Commission adopted this provision, as a 50-mile exemption, in
1952.
The second exemption gives drivers the flexibility to extend the
14-hour duty ``window'' by two hours once a week [49 CFR 395.1(o)]. The
two extra hours can be used by the driver to meet peak demands,
accommodate training, stage trucks for the next day's deliveries, or
complete required recordkeeping. This final rule adopts both of these
exemptions; however, as discussed later, the ``100 air-mile exemption''
is incorporated into the new regulatory regime provided for short-haul
drivers of small CMVs in today's rule. Today's final rule makes no
changes to the ``16-hour'' provision found at 49 CFR 395.1(o).
Comments
In response to the discussion of short-haul operations in the 2005
NPRM, the Agency received 18 comments addressing the need for different
HOS rules for this class of operation. Specifically, five carriers,
four trade associations or firms representing the construction
industry, two other trade associations, and seve
