Fatigue 2021

Fatigue has different causes. A distinction is often made between sleep-related fatigue and task-related fatigue. Given the many causes, almost everyone is tired sometimes. Consequently, fatigued driving is fairly common. For example, in a large-scale international survey between 20 and 25% of the car drivers indicated that, during the last month, they had driven at least once while they were so sleepy that they had trouble keeping their eyes open. Fatigued driving is relatively common among (international) truck drivers, people working in (night) shifts, young men, people with untreated sleep problems/disorders. Taxi drivers are also seen as a specific risk group for fatigued driving.
People who are tired tend to be less attentive and react less quickly and less adequately (e.g., more steering movements, more variation in speed and headway distance). Fatigue also affects mood and thus behaviour: tired people tend to get irritated and frustrated more easily. It is estimated that driver fatigue is a contributing factor in 15 to 20% of serious crashes, though the results of individual studies vary widely. Shares are higher for crashes involving trucks, for fatal crashes and for motorway crashes. When driving while fatigued, the risk of a crash increases considerably. A meta-analysis of 14 studies showed an increase in crash risk of 29% for fatigued drivers compared to those who were not fatigued.