Schedule-induced hours-of-service and speed limit violations among tractor-trailer drivers

Driver fatigue is well recognized as an important causational factor in accidents involving long-distance truck drivers. Drivers may drive while fatigued for a variety of reasons. Important among these is the assignment of difficult or unreasonable delivery schedules. Using self-reported data, the frequency of violation-inducing schedules is estimated during their ongoing movement for a sample of 498 long-distance drivers. Assuming average legal speed limits of 55 MPH, 26% of the drivers were found to have violation-inducing schedules. Solo drivers, drivers hauling refrigerated loads, regular route drivers, and those with longer current trip distances are the most likely to have such schedules. Also estimated were total weekly work hours. Assuming average attained travelling speeds of 50 MPH, the average driver drives 46 hours per week and works a total of 58 hours.