Version 1.0 of the Pooled Fund Study (PFS) Maintenance Decision Support System (MDSS) is being released during the fall of 2004. The PFS MDSS is the first public / private venture into operational application of maintenance decision support technologies. The PFS MDSS integrates in-situ, remotely-sensed, and forecast weather information with data gathered from Road Weather Information Systems (RWIS), road condition reporting systems, and winter road maintenance activities data collection platforms to provide maintenance personnel with a suite of decision support tools. The PFS MDSS approach focuses upon simulation of the ‘contaminant layer’ atop the pavement, integrating recent road condition, maintenance activity, and weather information to provide an ongoing assessment of the present state of the roadway. This assessment of the initial state of the contaminant layer is used in concert with weather forecast and available maintenance resources information to construct an initial/boundary value problem. Standard minimization techniques are used to find candidate maintenance actions that will maintain the required level of service in the most economical manner given available human, equipment, and material resources. The system also supports contaminant layer simulation for user-defined maintenance actions in a ‘what-if’ mode. The PFS MDSS software has been constructed to meet the stringent criteria of state information technology divisions, including the ability to run the graphical user interface at remote locations from a central state server.