Fatigue as a road safety issue has been highlighted at the recently released synthesis of the European Road Safety Observatory as prepared by the SafetyNet project. Fatigue leads to a deterioration of driving performance, manifesting itself in slower reaction time, diminished steering performance, lesser ability to keep distance to the car in front, and increased tendency to mentally withdraw from the driving task. Fatigue is a major factor in a large proportion of road crashes (range 10-20%). A person who drives after being awake for 17 hours has a risk of crashing equivalent to being at the 0.05 blood alcohol level (i.e. twice the normal risk).