Assessing Return on Investment of Freeway Safety Service Patrol Programs

Abstract

Safety service patrol (SSP) programs are widely used to help mitigate the effects of nonrecurring congestion and have become an increasingly vital element of incident management programs. In recent years, some state departments of transportation have initiated return-on-investment evaluations of their SSP programs. The purpose of this project was to use Virginia data to develop methods to evaluate and quantify the benefits of SSP programs; this involved developing a methodology to determine incident durations with and without SSPs for the Northern Virginia region and applying the results to a model to quantify the benefits associated with reductions in motorist delay, fuel consumption, and emissions attributable to SSP operations. To verify the general applicability of the methodology, the evaluation procedure was applied to the Hampton Roads, Virginia, SSP. The results showed that incident duration reductions attributable to SSP operations in these two areas resulted in benefit–cost ratios of 5.4:1 and 4.7:1, respectively. The methodology developed can be used by other agencies that have the means to collect and archive incident duration and location data. The amount of effort involved in applying the methodology is dependent on the type of data collected by the SSP and the state police and the level of integration of SSPs and computer-aided-dispatch databases in those regions.