THE SLEEP OF LONG-HAUL TRUCK DRIVERS

Background Fatigue and sleep deprivation are important safety issues f or long-haul truck drivers. Methods We conducted round-the-clock elect rophysiologic and performance monitoring of four groups of 20 male tru ck drivers who were carrying revenue-producing loads. We compared four driving schedules, two in the United States (five 10-hour trips of da y driving beginning about the same time each day or of night driving b eginning about 2 hours earlier each day) and two in Canada (four 13-ho ur trips of late-night-to-morning driving beginning at about the same time each evening or of afternoon-to-night driving beginning 1 hour la ter each day).Results Drivers averaged 5.18 hours in bed per day and 4 .78 hours of electrophysiologically verified sleep per day over the fi ve-day study (range, 3.83 hours of sleep for those on the steady 13-ho ur night schedule to 5.38 hours of sleep for those on the steady 10-ho ur day schedule). These values compared with a mean (+/-SD) self-repor ted ideal amount of sleep of 7.1+/-1 hours a day. For 35 drivers (44 p ercent), naps augmented the sleep obtained by an average of 0.45+/-0.3 1 hour. No crashes or other vehicle mishaps occurred. Two drivers had undiagnosed sleep apnea, as detected by polysomnography. Two other dri vers had one episode each of stage 1 sleep while driving, as detected by electroencephalography. Forty-five drivers (56 percent) had at leas t 1 six-minute interval of drowsiness while driving, as judged by anal ysis of video recordings of their faces; 1067 of the 1989 six-minute s egments (54 percent) showing drowsy drivers involved just eight driver s. Conclusions Long-haul truck drivers in this study obtained less sle ep than is required for alertness on the job. The greatest vulnerabili ty to sleep or sleep-like states is in the late night and early mornin g. (C) 1997, Massachusetts Medical Society.