Safety and Economic Evaluation of the Highway Safety Improvement Program: Is there a Return on Investment?

Abstract

The Highway Safety Improvement Program (HSIP) is a Federal-aid program aimed at achieving a significant reduction in traffic fatalities and serious injuries on all public roads. Projects are selected based on the potential reduction of severe crashes and the greatest return on investment. In this paper, a step-by-step process and methodology were developed to evaluate HSIP projects. The process and method were implemented to evaluate HSIP projects executed in Wisconsin between 2013 and 2019. Safety effectiveness evaluation and economic assessment were conducted using the Empirical Bayes (EB) method. Crash cost benefit of implemented projects was quantified to find the benefit–cost (B/C) for a horizon of 10 years and observed period of analysis. With data available from project evaluations, Crash Modification Factors (CMFs) for common treatments were developed. A total of 64 HSIP projects were evaluated. B/C ratios greater than one were observed in 43 projects. For a 10-year horizon, the aggregated B/C ratio was 2.71. Alternatively, using the observed data during the study period of each project, the observed overall crash cost benefit was equal to $72 million which corresponds to a B/C ratio of 1.10 (benefit already surpassed project costs at 3–5 years). Approximately 536 crashes were prevented which translates to seven lives saved, 380 injuries prevented, and avoided 1,067 property damage losses.