[Effect of fatigue on the fitness to drive]

The 1995 U.S. Department of Transportation files contain a statement that driver fatigue has been a major problem among road vehicle professional drivers, while the consequences of participation in public road traffic of drivers affected by fatigue represent a serious threat to the public safety. Therefore, studies on the causes and consequences of fatigue in drivers are of significant practical value. The authors of this work discuss definitions of fatigue and fatigue classifications relative to the location of the functional changes (physical and mental fatigue, general and local - muscular, ocular, auditory) and relative to intensity (acute, sub-acute, chronic fatigue and weariness), and duration Particular attention has been paid to the factors contributing to fatigue in drivers. These may be classified into two groups: 1. sleep-related (SR), i.e. cumulative sleep deficit, long wake time, and time of the day; 2. task-related (TR), i.e. factors related with vehicle driving and working (driving) time. Studies on the effect of fatigue on driving performance (longer reaction time, poorer vigilance, slower information processing, impaired recent memory) have been analyzed. The major effect of driver fatigue is that he/she becomes gradually diverted from the road and road traffic, with the resultant poorer driving performance. Thus, the effects of fatigue in a driver are comparable to those after alcohol intake. This paper also discusses the methods used to counteract and prevent fatigue.