Prolonged exposure to glare and driving time: effects on performance in a driving simulator.

Twelve experienced truck drivers drove a fixed-base driving simulator for two 8 h sessions, including: (1) no glare and (2) intermittent glare presented in the exterior rear-view mirrors to simulate headlights from following vehicles. The driving task combined vehicle control on straight and curved road segments with detection of pedestrians appearing alongside the road and targets appearing in the rear-view mirrors. The results provided no evidence to support the hypothesis that prolonged exposure to glare impairs driving performance. However, we found time-related changes in target-detection and critical tracking performance, some of which were consistent with established patterns of diurnal variation. Subjective sleepiness ratings also increased over time. The results were interpreted within a model according to which drivers are able to maintain effective performance at early levels of impairment, thus compensating for increasing feelings of subjective tiredness.