Probabilistic assessment of road vehicle safety in windy environments

Several wind- and weather-related accidents of road vehicles occur every year, especially at exposed locations where topographical features magnify the wind effects. The most notable ones involve high-sided vehicles. The objective of this paper is to investigate parameters influencing wind-related accidents of road vehicles. A general probabilistic model, based on reliability approach, is outlined and applied for assessment of road vehicle stability in windy environments. The numerical model is defined on a finite set of basic variables with prescribed probabilistic characteristics. The basic variables are wind velocity and direction; frictional coefficient; camber of the road and vehicle speed. The accident point is defined in the space of basic variables and the probability of accident is assessed. The theory presented is applied to a multitude of scenarios to explore the interrelation between the various basic variables and how they affect the probability of accident given in terms of the so-called accident index. The analysis demonstrates that wind-related accidents are the consequence of a combination of several basic variables as represented by the accident index. The study suggests that available methods of probabilistic mechanics and theory of reliability can be of value for analysis of wind-related traffic accidents and potential applications of the presented methodology are outlined.