The Michigan Department of Transportation (MDOT)’s strategic plan for Intelligent Transportation Systems (ITS) revolves around attaining and demonstrating key mobility, safety, productivity, energy and environment, and customer satisfaction benefits at a reasonable and sustainable level of investment. The research team was tasked with evaluating the return on investment of the newest major ITS construction projects, which have introduced a large number of new applications and devices. The evaluation was based on data from the different traffic operations centers (TOCs), surveying the public, and analysis with statistical modeling, microsimulation, and a tiered cost-benefit analysis.
A traffic microsimulation software package was used to quantify benefits from "with/without" ITS scenarios with regards to freeway incident management based on AADT, ITS device density, economic impact, and crash/incident history. This study identified highway segments with the highest potential for positive ITS benefit. The objective of corridor microsimulation was to quantify detailed benefits resulting from MDOT ITS. In this project, the research team selected a sample of representative corridors from each of the three MDOT TOCs. MDOT’s incident management programs strive to produce savings in congestion cost, reduce incident duration, reduce motorist delay, and improve safety by minimizing the probability of secondary crash occurrence.
Seven major MDOT freeway corridors were selected for the simulation study. The corridor characteristics under consideration for site selection included AADT, ITS device density, economic impact and crash/incident history. The goal of the study was to choose a representative selection of corridors whose analysis and subsequent results could be transferrable to other corridors statewide.
The overall estimated benefit-cost ratio for ITS deployments in Michigan is 3.16. Specific benefit-cost ratios were developed for four specific ITS devices and services:
- Dynamic message signs, 3.81
- Closed-circuit television, 3.95
- Microwave vehicle detection systems, 1.02
- Freeway courtesy patrol, 3.82