Introduction
Driving a car is a complex, multifaceted and potentially risky activity requiring both physiological and cognitive resources to maintain performance over time. A reduction in any of these resources can have dramatic consequences, resulting in crashes. Most people are aware of the dangers of driving while intoxicated, but many do not know that drowsiness also impairs judgment, performance and reaction times, just like alcohol and drugs do. The International Transport Forum at the OECD estimates that 20-30% of fatalities are due to driver sleepiness and fatigue [1], and in Europe, a survey across nineteen countries showed that the prevalence of falling asleep while driving in the previous 2 years is 17%, and amongst those who fell asleep, the prevalence of sleep-related crashes was 7% [2].