Correlation between Vigilance Level and Driving Performance: Influence of the Driving Duration and Circadian Rhythm

The purpose of the study was to examine the impacts of the driving duration and circadian rhythm on the vigilance level of the drivers and to identify the correlations between the vigilance and driving performance. Ten drivers performed a nearly 200-km motorway driving session on a driving simulator. The quantification of physiological vigilance level was evaluated using electro-encephalogram (EEG) and electro-cardiogram (ECG) recordings. Driving performances were measured using reaction time (RT) and standard deviations of speed (SDS). The results showed that driving duration had significant impacts on the drivers’ vigilance and driving performances, and a 2-h driving task had already decreased their vigilance level and deteriorated their performances. The impacts differed significantly by the initial mental states of the drivers. A certain time of rest was advised for all the drivers when they had already been driving for 2 h, which might reduce the probabilities of the traffic accidents.