The Pooled Fund Study (PFS) Maintenance Decision Support System (MDSS) is the product of an ongoing collaborative research and development project involving 13 state winter maintenance agencies and a private sector partner, Meridian Environmental Technology. Considerable field research has been performed over the course of the project in order to support the development of modules for simulating various processes of importance in winter maintenance. This synopsis will highlight the datasets that have been collected by the project (which are available for research application outside of the PFS MDSS), demonstrate what has been learned through the research permitted by these datasets, and identify numerous areas of the road weather science where the project has identified a continuing need for more field or laboratory research.