This study was the first of a series looking at the development of model work-rest schedules that have demonstrated effectiveness in managing driver fatigue. The aim was to develop a range of performance tests with demonstrated sensitivity for fatigue and for which the fatigue effects could be interpreted on the basis of a community-accepted standard for safety. Performance effects were studied in the same subjects over a period of 28 hours of sleep deprivation and following measured doses of alcohol up to approximately O.1 percent blood alcohol concentration (BAC). Subjects were 39 employees from the transport industry and the army. After 17 to 19 hours without sleep, corresponding to approximately 10.30 pm and just after midnight, performance on some tests was equivalent or worse than that at 0.05 percent BAC. Response speeds were up to 50 percent slower for some tests and accuracy measures were significantly poorer at this level of alcohol. After longer periods without sleep, performance reached levels equivalent to the maximum alcohol dose given to subjects (0.1 percent BAC). The results also demonstrated that not all types of performance tests were affected by sleep deprivation. Also, differences between the performance of drivers and controls suggested that drivers took a more conservative approach to performance. This study demonstrated which of a set of performance tests can be used in evaluations of fatigue and fatigue countermeasures. The findings also reinforce evidence that the fatigue of sleep deprivation is important and likely to compromise speed and accuracy needed for safety on the road and in other industrial settings. (A)
Samenvatting