Summary

Human factors overtook track defects as the leading cause of railway accidents in 1990, contributing to more than one-third of the 3,000 railroad accidents reported that year. The Hours of Service Act mandates that railroad engineers work no longer than 12 continuous hours, at which point they must be given at least 10 consecutive hours off duty. Yet the act may be having little effect on rail safety because start time variability--the change in work period start times from shift to shift--may be causing widespread fatigue among engineers. When combined with other factors, such as work during early morning hours, variable schedules can decrease performance levels. Reducing the maximum hours allowed per shift from 12 to 10 would at best affect only a small fraction of rail accidents, mainly because so few accidents attributable to human factors occur after 10 hours in an engineer's shift. More importantly, such a reduction could increase the variability of work period start times for those who regularly work such hours, actually increasing fatigue in some cases. GAO urges that to avoid even greater engineer schedule variability, Congress exercise caution if it changes the Hours of Service Act. These changes could lead to more widespread fatigue, particularly in the early morning hours. GAO summarized this report in testimony before Congress; see: Railroad Safety: Engineer Work Shift Length and Schedule Variability, by Kenneth M. Mead, Director of Transportation Issues, before the Subcommittee on Transportation and Hazardous Materials, House Committee on Energy and Commerce. GAO/T-RCED-92-68, June 10 (13 pages).

GAO found that: (1) the four railroads reviewed comply with the provisions of the Hours of Service Act and, 99.4 percent of the time, give engineers at least 10 hours off duty following a work period of 12 or more hours; (2) estimates show that engineers rarely work more than two consecutive shifts with 9 or fewer hours off duty between shifts; (3) analyses of accident data show that reducing the maximum number of hours allowed per shift may have little effect on the number of rail accidents that occur, because only 4.5 percent of all human-factors-caused accidents in 1989 and 1990 occurred after 10 hours in an engineer's shift; (4) reducing the maximum allowable work/off-duty periods to a 10-hours-on, 10-hours-off cycle would increase the variability of engineers' work cycles, increasing fatigue; (5) scientific research indicates that variability in work-cycle start times disrupts natural human sleep-wake cycles and can lead to fatigue and diminished performance; (6) the start time variability of engineers' work cycles was quite pronounced during the 2 a.m. to 6 a.m. time period; and (7) it could not isolate or quantify the extent to which fatigue caused by variable schedules contributed to accidents. GAO urged caution in considering any changes to the act, because greater engineer schedule variability could increase the potential risk of fatigue, particularly in the early morning hours.