Drowsiness at the wheel is recognised as a significant cause of accidents. Although the proportion of accidents only attributed to drowsiness is hard to evaluate, several international studies reckon that it could be attributed to 20% of serious accidents. This share is in fact similar to that of driving under the influence of alcohol (25%). Besides, the results of Vias institute study reveal that 4.8% of individual journeys in Belgium were undertaken as drivers showed signs of drowsiness. Knowing that individuals often underestimate their fatigue, this number could be even higher.

There are several warning systems designed to detect drowsiness but they all have very different operation modes and require an external validation. The scientific reliability of these systems as well as the subjective interpretation of warning signals should be further explored. Vias institute is currently conducting a study aiming at assessing the pertinence of warning signals from the users’ point of view (interpretation and reaction).