Driver fatigue is one of the biggest killers on the roads, playing a role in approximately 13% of Australian road accident deaths between 2012 and 2016. It is also one of the hardest accident causes to combat. In fact, driver fatigue poses a number of unique challenges to public authorities in their efforts to reduce the road toll. Fatigued driving is hard to police, and may affect drivers who are otherwise very responsible on the road. It is also a major risk factor for long haul heavy vehicle drivers, whose vehicles have a tendency to inflict high casualty rates when they cause accidents. Furthermore, while most drivers are aware that driving while fatigued is a bad idea, the majority of people are most likely to be on the roads in the mornings and the late afternoons – the two periods of day in which they are highly likely to be fatigued. It can also be very hard for a driver to determine when their fatigue levels reach the point where they pose an accident risk. Reducing the risk of accidents from driver fatigue therefore places the onus on drivers to understand the impact of fatigue on their driving ability, and to take the necessary precautions when they believe that they may be too tired to drive.