Abstract
With the objective of assessing the relationship between alignment indices and accident records, and the applicability of these indices to roadway design consistency evaluation for two-lane rural highways, a research project has been conducted at Madrid Polytechnic University. Data from eight Spanish highways with diverse terrain conditions divided into sections of homogeneous characteristics, excluding intersections, were analyzed. Ten alignment indices were considered, and their relation with crash rates over a 5 year period was analyzed. Based on the results of the analysis, the most suitable indices to evaluate roadway design consistency were identified. Additionally, threshold values of the selected indices for consistency rating of roadway segments were established. This consistency rating method was applied to a sample set of Spanish highway segments. The results show good agreement with those obtained with the Interactive Highway Safety Design Model (IHSDM) Design Consistency Module.
