The Impact of Hours-of-Service Regulations on Transportation Productivity and Safety: A Summary of Findings from the Literature

INTRODUCTION The hours of service (HOS) regulations were first introduced by the now-abolished Interstate Commerce Commission (ICC) in 1937 as a way to protect the safety of long-haul truckers. The HOS's main purpose is to prevent truck accidents caused by driver fatigue. This is accomplished by limiting the number of driver working hours per day and week. Driver working hours include the time spent on loading, unloading, driving, handling freight, preparing reports, preparing vehicles for service, or performing any other duty pertaining to the transportation of passengers or property. The main reason for limiting driver working hours is to prevent fatigue by keeping drivers on a 21- to 24-hour schedule, maintaining a human body's natural sleep and wake cycle (so-called circadian rhythm). Drivers are required to take a daily minimum period of rest and are allowed longer weekend rest periods to combat sleep deprivation, cumulative fatigue, and time-on-task fatigue effects that accrue on a weekly basis (Federal Motor Carrier Safety Administration, 2006). Despite their intent to enhance traffic safety, HOS regulations have become sources of controversy because it is hard for the policy maker to determine exactly how long drivers should work and sleep for their safety. As such, there were numerous proposals to amend HOS regulations between 1962 and 2009, but none were ever finalized due to contentious debates over their effectiveness in enhancing traffic safety. One of the most notable proposals of those includes the highway reauthorization bill recently passed by the U.S. House of Representatives, which contained several important amendments for HOS regulations that aimed to balance the requirement for highway safety and the need for effective trucking services in the United States. Amended HOS regulations introduced by the U.S. Federal Motor Carrier Safety Administration (FMCSA) in 2003 and 2005 were generally well received by drivers, carriers, and shippers, although carriers seek more flexible sleeper berth rules. The main theme of the 2003 HOS rules is to increase an opportunity for restorative sleep by increasing the amount of off-duty time by two hours. To elaborate, these rules allowed truck drivers to drive a maximum of 11 hours after 10 consecutive hours off duty. However, truck drivers are prohibited to drive beyond the 14th hour after coming off duty, following 10 consecutive hours of duty. The 2003 HOS rules were further refined in 2005 which remained virtually unchanged as of 2008, because of a decision by the United States Court of Appeals for the District of Columbia Circuit in Public Citizen et al. versus Federal Motor Carrier Safety Administration (374 F.3d 1209) on July 16, 2005, which stated the 2003 HOS rules did not consider the impact of rules on driver health (Blanchard, 2004). As summarized in Table 1, the 2008 HOS rules intended to increase potential for quality sleep by mandating commercial motor vehicle (CMV) drivers to take at least 8 consecutive hours in the sleeper berth plus two consecutive hours either in the sleeper berth, off duty, or any combination of the two. Unfortunately, these amended regulations were still attacked by the International Brotherhood of Teamsters and public safety advocacy groups such as Public Citizen, Parents against Tired Truckers (PATT), and Citizens for Reliable and Safe Highways (CRASH) despite the fact that truck crashes and driver fatalities have fallen in the recent years even as more freight has been moved since their enactment (Cutler and Regan, 2007). To elaborate, the 2006 fatal crash rate for large trucks stood at 1.93 fatal crashes per 100 million vehicle-miles-traveled. This rate broke the previous low of 1.97 fatal crashes per 100 million vehicle-miles-traveled in 2002. The large truck-involvement rate fell to 2.12 per 100 million vehicle miles traveled, down from 2.21 a year earlier. The fatality rate declined to 2.24 per 100 million vehicle-miles-traveled, down from 2. …