1666607 - Validating a New Approach for Identifying Safety Improvement Sites on Rural Highways

The research presented in this paper examines a new proposed approach for identifying safety improvement sites on rural highways. Unlike conventional approaches, the proposed approach does not utilize crash history but rather utilizes classified variables for traffic volume, geometric, and roadside characteristics that do not require exact data or extensive technical expertise. The research validates the performance of the proposed approach using extensive field data from rural two-lane highway segments in the state of Oregon including traffic, roadway, and crash data. The performance of the proposed approach was compared to two of the well-established methods, namely:  the Empirical Bayes (EB) and the Potential for Safety Improvement (PSI) methods while using observed crash history as a reference. The study findings suggest that using crash density for highway segments, the performance of the proposed method was lower than that of the EB and PSI methods. This is despite the high R-square value of 0.934 of the predictive model used in this method. However, when using crash frequencies for highway segments, the performance of the proposed method was found comparable to the well-established EB and PSI methods.