A Systematic Approach to Identifying Traffic Safety Needs and Intervention Programs for Indiana: Volume Iâ•flResearch Report

The Joint Transportation Research Program serves as a vehicle for INDOT collaboration with higher education institutions and industry in Indiana to facilitate innovation that results in continuous improvement in the planning, design, construction, operation, management and economic efficiency of the Indiana transportation infrastructure. NOTICE The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views and policies of the Indiana Department of Transportation or the Federal Highway Administration. The report does not constitute a standard, specification or regulation. Abstract This report presents the results of JTRP Project " A Systematic Approach of Identifying Safety Intervention Programs for Indiana (SNIP2), " which aimed to develop SNIP2 to support identification of roads that have excessive crashes of the types defined by the user. In addition, this tool is capable of selecting the best combination of high‐crash roads and relevant safety interventions that maximizes the safety benefits and keeps the total cost within the budget and other user‐defined constraints. Unlike other studies considering the implementation time of safety projects, the optimization objective of SNIP2 is to identify an optimal combination of countermeasures renewable within a long time horizon. This simplification is accomplished by representing the projects through their annualized costs and benefits. It allows consideration of many projects for large road networks and it makes the SNIP2 suitable for identification of safety focus areas in strategic safety plans. The SNIP optimizer – a heuristic approximation of a large‐size mixed integer knapsack problem based on a greedy search was extensively tested and evaluated. It was found producing optimal or near‐optimal solutions in a sufficiently short time. Another research result is a comprehensive catalog of countermeasures for Indiana – a list of countermeasure names, road and crash conditions for the countermeasure relevance, corresponding crash modification factors, and countermeasure costs. The SNIP2 is computer software developed with close collaboration with the INDOT future users. It includes an updated crash and state road database. A user's manual describes on the necessary details of the software and various aspects of its use. Two example studies are also included in the manual to illustrate its use and to better presents the SNIP2 features. A systemic approach to identifying road locations that exhibit safety problems was provided by the Safety Needs Identification Program (SNIP) developed by the …