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 the Federal Motor Carries Safety Administration (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 assesses 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 have less than 168 hours between their restart periods and those drivers who have 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: (1) electronic logging devices (ELDs) (which track drivers’ time on duty); (2) psychomotor vigilance tests (PVTs) (which measure alertness); (3) actigraph watches (which assess sleep); (4) camera-based onboard monitoring systems (which record or measure SCEs and driver alertness); and (5) smartphone-based self-report questionnaires that measure sleepiness, stress, hours slept, and caffeine intake. An initial study plan, which was peer-reviewed by a panel of independent experts with relevant medical and scientific qualifications, was published in March of 2015. The final report and findings have undergone 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 is available at: