* Corresponding author. Journal of Wind Engineering and Industrial Aerodynamics 74—76 (1998) 1079—1090 Probabilistic assessment of wind related accidents of road vehicles: A reliability approach Ragnar Sigbjo¨rnsson, Jo´nas Tho´r Snæbjo¨rnsson* Engineering Research Institute, University of Iceland, Hjardarhagi 2-6, IS-107 Reykjavik, Iceland Abstract A general probabilistic model for assessment of road vehicle accidents in windy environments is presented. The limit states of safe performance are outlined and the accident point is defined in the space of basic variables. The probability of accident is evaluated using a so-called safety index approach. The theory outlined is used to analyse a particular bus accident by setting up scenarios based on available information. The methodology presented has several potential applications, such as in accident analysis, and in improving the design of roads and highways by pointing out potential accident spots as well as in devising preventive measures to improve traffic safety in windy environments.  1998 Elsevier Science Ltd. All rights reserved. Keywords: Accident risk; Aerodynamics; Dynamics; Reliability; Road vehicles; Saftey index; Wind engineering 1. Introduction In recent years wind-induced accidents of road vehicles have been an increasing problem in Iceland. These accidents seem most common at exposed locations where topographical features of the landscape magnify the wind effects. Further, the most notable ones involve high-sided vehicles like buses and trucks with trailers. This paper deals with such an accident on October 1995 when a bus with 41 passengers went off the road in a high cross wind and rolled over. This resulted in two passengers being killed and leaving the others with minor to severe injuries. The objective of this paper is to analyse, in general probabilistic settings, this particular incident. 0167-6105/98/$19.00  1998 Elsevier Science Ltd. All rights reserved. PII: S 0 1 6 7 - 6 1 0 5 ( 9 8 ) 0 0 0 9 9 - 3