The present study aimed to identify overload threshold due to driving situation complexity and driving practice. Moreover, subjective levels of tension [mental stress] and vigilance were analyzed as they can respectively influence workload and performance. Material & Methods: Thirty-two participants [9 novices aged between 18-20 who obtained their driving license within the last two months, 9 drivers aged 21 arriving at the end of the three-year probationary period, and 14 drivers aged between 23-30 with at least five years of experience] were randomly assigned to three situations with different levels of complexity [22.5 kms each] in a driving simulator. The less complex situation consisted in a straight national road, without any traffic. The moderately complex situation included right and left curves. The most complex situation had double and sharper curves, with oncoming traffic. In each situation, three pedestrians crossed the road in front of the participants. Self-reported levels of tension, vigilance and workload were collected by questionnaires between each driving situation. Objective driving performance [number of collisions with pedestrians] was also analyzed. First analyses showed that overload threshold is earlier for novice drivers than for more experienced drivers. Indeed, the number of collisions with pedestrians, subjective levels of workload and tension were significantly higher for novice drivers. Nevertheless, drivers with three years of experience had significantly lower number of collisions with pedestrians, subjective levels of workload and tension, and higher subjective vigilance than drivers with at least five years of experience. It thus seemed that overload threshold arrives earlier for the most experienced drivers than for drivers with three years of driving experience. Situation complexity didn't reduce overload threshold depending on driving experience.
