Twenty per cent of all road accidents resulting in death or serious injury are caused by drowsiness at the wheel (Anon., 1999). This tiny bit of information illustrates just how serious and hazardous drowsy driving really is. Even modest amounts of sleep loss over short periods (about two hours a night over one week) accumulate and manifest themselves as an irresistible tendency to fall asleep during inappropriate or dangerous situations, like driving (Feyer, 2001). I am one of those people who have never, ever, fallen asleep during anything. Not during a single lecture, not through one movie, whether at the theatre or in my home, and not while driving have I ever had the impulse to close my eyes. It does not matter how bored or how tired I am; I am always just too interested and have to know what will happen or be said next. This is all very humorous to me, because now that I think about it, I am tired, I mean totally exhausted, so often, and not once have I nodded off. Compared to most individuals, I have an exceptionally long attention span and lengthy drives in the dark do not bother me, even if I am exhausted. I consider myself lucky, in that regard. Unfortunately, lack of sleep is not seen as a risk and rest is not given high priority in the face of competing activities. There is no simple objective test of fatigue, equivalent to a breath analyzer for alcohol, that can be applied after an injury has occurred (Feyer, 2001). .
A study done by Williamson and Feyer sparked intense discussion in the media as well as among medical professionals. The authors compared the relative effects of sleep deprivation and alcohol on the ability of 39 individuals (37 men and 2 women) to execute computerized performance tests. After 17 to 19 hours without sleep, subjects' test results were equivalent to or worse than those of people with a blood alcohol concentration of 0.05%. Specifically, the authors found that skills with low cognitive demand, such as simple reaction time, were affected by sleep deprivation much more than higher cognitive skills, such as logical reasoning and memory (Williamson, 2001).