Mobile phone use and driving under the influence of alcohol are not the only examples of irresponsible driver behaviour. Tiredness when driving a vehicle is said to be responsible for 300 deaths per year. Astonishingly, almost half of male drivers and 22% of female drivers admit to having fallen asleep at the wheel. If we assume (and it seems reasonable to do so) that even more people are injured than killed as a result of accidents caused by tiredness, it is clear that tiredness while driving is a major road safety issue – and entirely preventable. If we wish to preserve our own lives and those of others we should not drive a car knowing that we have had insufficient sleep or rest to drive safely.