Harnessing the Power of Microscopic Simulation to Evaluate Freeway Service Patrols1

Abstract

Public agencies have been increasing their use of freeway service patrols (FSPs) to help with incident detection, verification, response, and motorist support. Using the microscopic simulation software PARAMICS, this study evaluated the benefits of FSPs in reducing the duration of roadway blockage, following a crash and the resulting vehicle delay. A customized PARAMICS model was developed for random spatial and temporal crash generation, and the modeling of different number of FSPs and response policies through an application programming interface. Analysis of the simulation results revealed that both response policy and the number of FSPs affected the crash response times and consequently the duration of blockage and vehicle delays. The effects of different response policies diminished as the number of FSPs increased. Benefit-cost analysis indicated that FSP programs can obtain a maximum benefit-cost ratio of 22:1, which decreases as the number of FSPs increases, number of crashes per year decreases, and the discount rate increases.