Development of supporting tools for safety management of non-urban roads, in Israel

To promote the Safe System approach, tools for road infrastructure safety management are required to be implemented by road authorities. A systematic use of such tools is not yet common among countries. In Israel, a safety management system was established by the National Transport Infrastructure Company, to provide for continuously improved safety levels of the non-urban road network. One of the system’s functions lies in the identification and treatment of hazardous-locations, while applying an empirical Bayes evaluation. To support the system needs, in the study, accident prediction models were developed for Israeli conditions, using simultaneous data on road infrastructure, traffic exposure and accident occurrences. The study’s database included 2,545 junctions and 8,413 road segments of 0.5 km in length. In the model development, first, the form of relationship between traffic volumes and accidents was explored using generalized additive models, and then, negative-binomial regression models were fitted. Depending on data availability for various types of sites, models were developed for seven types of junctions, including interchanges, signalized junctions, un-signalized junctions and roundabouts, and for five types of road segments such as: motorways, dual-carriageways, two-lane roads with and without horizontal curves, and two-lane roads with median barriers. In line with the empirical Bayes procedure, separate models were fitted for slight, serious and fatal accidents, and weights were assigned based on the economic costs. The developed tools are used systematically for the identification of hazardous-locations on the road network, and assist in other safety evaluations, within transport projects and road safety programs.