Impact of traffic states on freeway crash involvement rates

► In this study we proposed a method to understand the freeway crash occurrence relating to traffic states. ► First, we developed 4 traffic state definitions for a freeway section, FF, BN, BQ, CT that are thought to be influencing the driving pattern. ► We aggregated traffic accidents data and related them to the traffic states. ► The result shows promise to be used for various safety performance measurement including hot spot identification and prediction of the number of crash involvements.