Excessive daytime sleepiness and driving: regulations for road safety.

Individuals who fall asleep at the wheel usually do so because they are sleep deprived. It is likely that they are aware of the circumstances leading to sleepiness and of feeling sleepy before the event. Nevertheless, sleepiness sufficient to cause or contribute to an accident may involve a disorder of sleep, and little attention has been given to such disorders in the consideration of accident prevention. In this context, the Department for Transport brought together a group to explore the potential significance of sleep disorders in accidents. The Driver and Vehicle Licensing Agency has clarified existing regulations, particularly those that concern vocational drivers.