In spite of considerable improvement of road safety these last years, the level of the accidentology is always worrisome in France in 2010. A better management of the difficulties in bend would allow to avoid 15 percents of fatal accidents. In the research programme on infrastructures and road safety of the IFSTTAR, it was decided to investigate in details the concept of vehicle trajectories in bend. Then we propose in this paper a methodology to estimate probability of failure of vehicle in bend. For that, we propose an original approach based on the use of experimental data.
