The Michigan Department of Transportation (MDOT) recently completed architectures and pre-deployment plans for five of the state's seven regions. The paper provides benefit-cost calculations for two weather-related deployments, Road Weather Information Systems (RWIS) and Maintenance Tracking using Global Positioning System (GPS) for Maintenance Vehicles and Snowplows. The potential benefits of RWIS combined with Maintenance Tracking are: crash reduction during adverse weather, and operating cost savings through more efficient use of winter maintenance resources.
Data outputs were obtained from the statewide travel demand model to use as inputs into the ITS Deployment Analysis System (IDAS) model. The model data included both network files and travel demand files representing daily volumes for 2010. The project team used a combination of national default values, values developed for the Southeast Michigan ITS Deployment Study conducted from 2000 to 2002, and values estimated based on research conducted specifically for the project as the estimated impact of the ITS deployment. Annualized capital costs were added to operational and maintenance costs to estimate annual expenditures.
The table below shows the benefits and costs of proposed RWIS deployments in four regions in Michigan. The benefit-cost ratios are higher in the Bay and Grand regions where fewer Environmental Sensor Stations( ESS) are proposed but where more motorists are served by the system. Travel time savings provide a significant proportion of the benefits in these regions. In the more rural North and Superior regions a higher proportion of benefits are found in crash reduction and operating costs, with less in travel time savings due to significantly lower traffic volumes.
Figure 1: Benefit-Cost Analysis from Michigan's DOT Regional Pre-deployment Studies
Benefits and Costs
|Travel Time Savings|
|Total Annual Benefits|
Both urban and rural ITS applications suffer from a lack of empirical data on the impacts of ITS technology. Rural and small urban areas can increase their data collection efforts by: closely cooperating with law enforcement to obtain data on incident response times, travel delays, and crash rates; tracking the impacts of improved weather information winter maintenance; and surveying customers on what travel information they wish to receive.