The safety engineer must have an accurate measure of the current safety of a location and a prediction of how alternative treatments will affect future safety. The United States FHWA is developing the Interactive Highway Safety Design Model (IHSDM) as an add-on module for CAD-based systems. It will include a suite of evaluation tools for assessing safety impacts of layout decisions. A key component is a crash prediction algorithm. Currently it is aimed at predicting the number and severity of crashes for alternative designs by combining historic al accident data for a given site, regression model output and accident modification factors (AMFs) based on past research and expert judgement. This paper concentrates on the work with the AMFs developed for both road segments and junctions.
Samenvatting