Sleep Deprivation and Traffic Accidents

Copyright 2006 Mary Desaulniers

Ten years ago, a former colleague of mine, a fine teacher and person, was tragically killed in a car accident in British Columbia. He was on vacation with his daughter who miraculously survived the accident. What happened was a classic case of sleep deprivation: my friend was anxious to make his way to a chosen destination and despite his fatigue and the fact that he had been on the road for over 6 hours, he made the decision to drive through the night. He never made it there.

That there is a direct correlation between sleep deprivation and traffic accidents cannot be disputed. In 1998, 24,318 deaths were cited from accidents related to sleep deprivation in the US. There were as well 2, 474,430 disabling injuries resulting from accidents where decreased mental efficiency and attentiveness due to sleep loss was the major causative factor. In fact, a major review conducted in 1996 suggested that the oil spill of the Exxon Valdez, the destruction of the space shuttle Challenger, the nuclear accident at Chernobyl( costing over 50,000 lives) and the near nuclear accidents at the Three Mile Island and Peach Bottom reactors were all associated with sleep deprivation of the personnel involved.

Sleep deprivation is often caused by sleep disorders which are unknown to the subjects themselves. Sleep apnea, for example, is a common cause for sleep deficit. A study at the Sleep Disorders and Research Center of Stanford University Medical School showed that truck drivers identified with sleep disordered breathing had a two-fold higher accident rate than drivers without sleep-disordered breathing. Sleep disordered breathing, commonly known as sleep apnea, affects 15 million people in the United States. This condition, characterized by suffocation and oxygen deprivation which wake the subjects up several times in the course of the night, is responsible for daytime sleepiness and fatigue. Put these subjects on the highway and we have a recipe for disastrous traffic accidents.

Perhaps an examination of the influence sleep deprivation has on our mental acuity and performance level can shed light on how we can protect ourselves and others from the disastrous consequences of sleep fatigue.

What happens to you when you are sleep deprived? According to the Traffic Research Center, these are the influences of sleep deprivation on performance:

a) Slower reaction time: sleeplessness slows down your reflexes; reaction time slows down, preventing you from stopping in times of danger.

b) Decrease in concentration levels: When you are overly tired, your attention span decreases. Most people are subject to a decrease in attention every 90-120 minutes; however, sleepiness makes this decrease even worse and it can cause accidents when you fall asleep at the wheel.

c) Disorder in information processing: Sleepiness is very much like being under the influence of alcohol or drugs. When you are sleepy, your mental and psychomotor skills diminish. In one study, a group of subjects were kept awake for 28 hours; another group was given alcoholic drinks every half hour. When both groups were tested for hand-eye coordination, the ones who were sleep deprived performed equally bad as the ones with 0.5 blood alcohol level.

What are the factors that have a direct effect on a driver