The purpose of this paper is to study traffic conditions that precede the occurrence of road accidents, and to point out the relation between traffic conditions and accidents. It is to combine traffic variables into indicators; then to constitute different sets of traffic conditions and accidents; and, according to the obtained results, to highlight the variations in the accident risk according to different categories of analysis; and finally to propose to use some indicators in certain contexts in order to predict potential danger, and then warn drivers. Here a traffic database (including individual speeds and headway) is analyzed in relation with the accidents occurred. The proportion of vehicle-kilometers when an accident occurs, in the case of high values of the indicator, has been matched with the same proportion in the case of low values. A tentative to take into account changes in kinematics variables due to local conditions and traffic conditions has been made. The results contribute to validate the link between accident and some indicators, based on occupancy, speed and relative speed.
