Empirical Evaluation of a New Heuristic Network Screening Methodology for Rural Highways

Identifying safety improvement sites (network screening) is a critical step in road safety management programs. The overall effectiveness of these programs largely relies on the robustness of the network screening method in identifying sites with high potential for safety improvements. This study investigates the performance of a new proposed methodology for network screening on rural roads. The new method, originally proposed for use on rural low-volume roads, is simplistic in that it does not require exact and detailed information on traffic and geometric characteristics and can still be applied in the absence of crash data. The performance evaluation is conducted using a sample of 1495 miles of rural two-lane highway segments in Oregon. The effectiveness of the proposed method is assessed using observed crash history and compared to the well-established Empirical Bayes method as a reference. The effect of traffic level on the performance of the proposed method was evaluated using separate analyses for lower and higher traffic volume segments. Study findings indicate that the effectiveness of the proposed method in identifying sites with potential safety improvements is overall high and slightly exceeded that of the more sophisticated and data-intensive Empirical Bayes method. When data was stratified by traffic volume, the proposed method was found more effective for lower volume roads, however, the Empirical Bayes outperformed the proposed method for higher volume roads.