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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Commercial Motor Vehicle Driver Restart Study


The Commercial Motor Vehicle (CMV) Driver Restart Study was designed to measure and compare the fatigue and safety performance levels of truck drivers in a naturalistic environment while using two different versions of the hours-of-service (HOS) restart provisions.


In the Consolidated and Further Continuing Appropriations Act of 2015, Congress directed FMCSA to conduct a CMV driver restart study comparing 5-month driver work schedules and assessing operator fatigue and safety critical events (SCEs) among participating CMV drivers who operate under:

  • The restart provisions in effect between July 1, 2013, and December 15, 2014 (i.e., 2-night rest period); and
  • The restart provisions in effect on June 30, 2013 (i.e., 1-night rest period).


The study compared 5-month work schedules and assessed SCEs (e.g., crashes, near-crashes, and crash-relevant conflicts), operator fatigue/alertness, and short-term health outcomes among CMV drivers operating under a 1-night rest period versus drivers operating under a rest period with 2 or more nights. The study also analyzed the safety and fatigue effects on CMV drivers who had less than 168 hours between their restart periods and those drivers who had at least 168 hours between their restart periods. Drivers were recruited from small, medium, and large fleets across a variety of operations (long-haul, short-haul, and regional) and different sectors of the industry (flat-bed, refrigerated, tank, and dry-van). FMCSA would like to thank the many CMV drivers and companies who volunteered to participate in this study.

The study used data collected from:

  • Electronic logging devices (ELDs) (which tracked drivers’ time on duty).
  • Psychomotor Vigilance Tests (PVTs) (which measured alertness).
  • Actigraph watches (which assessed sleep).
  • Camera-based onboard monitoring systems (which recorded or measured SCEs and driver alertness).
  • Smartphone-based self-report questionnaires that measured sleepiness, stress, hours slept, and caffeine intake.

A study plan, which was peer-reviewed by a panel of independent experts with relevant medical and scientific qualifications, was published in April of 2015. The final report and findings underwent a similar independent peer review. The Secretary submitted an outline of the study’s scope and methodology to the U.S. Department of Transportation (USDOT) Inspector General. The Secretary also submitted the final report to the Inspector General.


A final report containing study findings.


February 2015: Independent peer review panel approved the study design
March 2015: USDOT Inspector General approved the study plan; data collection began
April 2015: Recruitment of CMV drivers for the study concluded
September 2015: Data collection ended
December 2015: A final report submitted to the Office of the Secretary
January 2017: Final report submitted to the USDOT Inspector General
March 2017: USDOT Inspector General letter report summarizing independent review findings submitted to Congress
March 2017: Final report submitted to Congress; full report, report to Congress, research brief, and public-use dataset published


FY 2015: $4,000,000.00

Current Status:

FMCSA submitted and published a summary report to Congress in March of 2017, following an independent review of the final report and study findings by the Office of Inspector General. In addition to the report to Congress, the full report, research brief, and public-use dataset are available for download.


Virginia Tech Transportation Institute