GIS has been effectively used for snowplow routing and facilities location analysis in four counties and a state DOT district. Variations in speed, number of lanes, number of plows per route, cycle times, and plowing priorities are examples of the complexities that had to be dealt with. Objectives were to effectively allocate plows to garages, close or combine several garages, or build a new garage. In all cases, GIS was effective in finding alternatives that made the system more efficient. For the DOT in Minnesota, a potential savings of about $500,000 per year was the result of an alternative.