Sleep-Wake Schedules, Driving Management, and Traffic Accidents

Sleep-Wake Schedules, Driving Management, and Traffic Accidents 

Until the mid 90s, no study demonstrated the main factors responsible for sleep-related accidents. We questioned, apart from organic sleep disorders, whether modifications of the sleep-wake schedules could be responsible for sleepiness at the wheel. Studying large populations of drivers (22,23), we demonstrated that long-distance driving was frequently associated with sleep curtailment. Our first study (22), performed on a freeway rest stop area in 1993, showed that 50% of drivers (n = 567 drivers) reduced their sleep duration in the 24 hr before departure for a long-distance journey. Ten percent of drivers had no sleep in the 24 hr before the interview. These stunning results could have been explained by a 

Sleep deprivation affects not only automobile drivers but also many truck drivers. In a study of professional U.S. truck drivers, Mitler et al. (25) recorded the EEG of 20 drivers on four different work schedules. This study demonstrated a mean duration of sleep of 4.78 hr in a 5-day period. Fifty-six percent of drivers presented at least 6 noncontinuous min of EEG-recorded sleep during the driving 

We conducted a study on 227 professional European drivers interviewed at a rest area (26). The drivers were found to have a fairly consistent total nocturnal sleep time during their work week, but on the last night at home prior to the new work week there was an abrupt earlier wake-up time associated with a decrease in nocturnal sleep time. The results showed that 12.3% of the drivers had slept less than 6 hr in the 24 hr prior to the interview and 17.1% of the drivers had been awake more than 16 hr. These results confirm those of Mitler et al., and suggest that an improvement of driving regulations is required to increase professional drivers safety. 

In 1995, a study by the National Transportation Safety Board on fatal accidents in professional trucks drivers (27) showed that the mean duration of sleep among drivers was below 6 hr of sleep in the last 24 hr before the accident. Connor et al. (8) showed that sleepiness at the wheel increased the risk of causing a traffic accident by 8.2-fold. Sleeping less than 5 hr in the 24 hr before the accident and driving between 2 and 5 a.m. were also significant risk factors for accidents [odds ratio (OR) = 2.7 and OR = 5.6, respectively], 

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