Maintenance Decision Support Systems (MDSS) are computer-based logic systems that emulate the decisions made by highway maintenance personnel during winter maintenance operations. Five Midwestern states initiated a pooled fund study in November 2002 to develop and test an operational MDSS in conjunction with Meridian Environmental Technology. The project is a naturalistic approach to modeling maintenance decision options. The core of the model is the decision logic that replicates what maintenance personnel do routinely to address winter maintenance issues. Input into the decision process include: weather observations, detailed weather forecasts, observed road conditions, forecasted road conditions, recent maintenance practices, and available maintenance resources. The output displays those maintenance practices that are deemed the most effective options within the framework of local practices.

The MDSS is built within the infrastructure of the ITS architecture in an open, plug and play design. Much of the decision logic deals with the physics and chemistry of the “contaminant” layer immediately on top of pavement surfaces, the layer comprising snow, ice, water, chemicals, abrasives, and other extraneous materials. MDSS addresses the conditions of multiple, discrete, highway segments of uniform character. The model is initialized with existing contaminant layer conditions and determines one or more response scenarios based upon forecasted weather conditions, available resources, and local policies and practices. The MDSS recommends optimal maintenance practices to minimize the effects and costs of winter maintenance and displays these options as default output. Users of MDSS may select their own preferred response options and allow the system to determine the projected state of the contaminant layer based upon the forecasted weather and the specified maintenance actions. Users may also test a number of “what-if” scenarios.