The impact of driver fatigue on driving safety is a complex one. Within commercial road transport, the core issue is one of working time and the opportunity this offers for rest and recuperation from work, together with the possibility of presenting for work unimpaired by fatigue and loss of sleep. However, powerful economic and social forces influence and control the normative pattern of work of commercial drivers. Working time is, after all, one of the basic economic inputs to production and transport. Consequently, the safety argument too often has been brushed aside in the face of a commercial logic that requires flexible and on time transportation of goods and passengers, in many cases spanning the 24-hour cycle.