Sleep, work schedules and accident risk in South African long-haul truck drivers

Abstract

ALLING ASLEEP AT THE WHEEL HAS BEEN implicated in 24% of heavy-vehicle road accidents in South Africa. We compiled a questionnaire relating driving, sleep, and social habits with accident reports. In total, 102 male truck drivers aged 43 ± 8 years (mean ± s.d.) with 16 ± 8 years of professional driving experience participated in the study. Three-quarters of the drivers reported being tired at work because of working long hours (93 ± 30 hours/week) and half reported insufficient sleep (5.4 ± 2.3 hours/day) as a reason for their tiredness. While sleeping in their truck berth, almost eight out of 10 drivers reported that their sleep was interrupted, mostly due to noise. Sixty-two per cent of truck drivers admitted to nodding off at the wheel, which was associated with interrupted sleep. Drivers who reported signs of sleepdisordered breathing or other sleep complaints had an increased likelihood of having a sleep-related accident. These drivers also were more likely to have a body mass index greater than 25 kg/m 2 , and have a collar size larger than 40 cm. In common with drivers elsewhere, many South African long-haul drivers work illegally long hours, often to supplement their income and meet company deadlines; thus their sleep is restricted and they feel sleepy while driving, all factors associated with increased accident risk. Driving deprived of sleep poses a danger to all on the road; responsible trucking companies should ensure that drivers have adequate rest times in conditions conducive to sleep. Regulation of infringements at the company level would contribute substantially to an improvement of working conditions, as well as driver performance and well being.