Risk assessment for road accident prevention

This study represents just a part of a wider research that concerns the quality control of road project thanks to an hazard analysis approach. This approach allows to validate a road project in relation to the actual traffic conditions and expected human behaviours. It is characterized by a probabilistic point of view and enables to compute the probability of a road accident occurrence and evaluate the effectiveness of any action for road safety increasing. The most promising way to investigate and calculate the probabilities of each branch of the tree of events that depend on human factors is the multidisciplinary study based on driving simulation in virtual reality. Particularly the drivers’ risk threshold during passing manoeuvre is here investigated, using Virtual Reality simulations, and discussed. Traffic flow conditions and mobility motivations influence risk acceptable thresholds and driving behaviours of road users. For each case study different scenarios with increasing traffic flows have been implemented and the successfully ended passing manoeuvres, the aborted ones, the hazardous ones and the accidents have been computed. The final results and the significance of the experiments make it possible a generalization for road project once defined the roadway and traffic conditions corresponding to critical drivers’ risk acceptance.