DEVELOPMENT OF A METHODOLOGY TO IDENTIFY AND CORRECT SLIPPERY PAVEMENTS. FINAL REPORT

Traditionally, the most common action conducted by state and local highway agencies to prevent accidents on wet pavements has been skid resistance surveying of roads. However, there is strong evidence, confirmed by analysis of data from 308 road sites, that pavement skid resistance correlates poorly with the number of wet accidents and thus is not a reliable measure of wet pavement safety. In this study a probabilistic model of traffic safety under wet conditions was developed. The model of the Wet Pavement Index incorporates many variables, other than skid resistance, that affect safety, such as average daily traffic, driving difficulty, and wet weather exposure for a particular section of roads. The population of roads was divided into groups of roads having similar characteristics, and separate models were developed for different groups.