This Phase One report documents a three-year research program by the Arizona Transportation Research Center to study possible practical applications of vehicle and infrastructure-based technologies. The project has reviewed, evaluated and demonstrated Intelligent Vehicle and Automated Highway System concepts that may improve the safety and efficiency of Arizona's highway system, particularly in winter maintenance operations. The key accomplishment of Phase One was to develop a research partnership with the California Department of Transportation (Caltrans) in their Advanced Snowplow (ASP) program. The Caltrans prototype plow, guided by discrete magnetic markers in the roadway, features lane position indication, lane departure warning, and a forward collision warning radar system.