A passive infra-red guidance system and method for augmenting operation of a vehicle on a roadway includes at least one forward-looking infra-red imaging sensor mounted on the vehicle in operative communication with an image processor tied into the vehicle's operational system. The system identifies the presence of one or more melting agents arranged on the roadway using thermal imaging to detect a thermal contrast between the portion(s) of the roadway surface treated with the one or more melting agents and the untreated portion(s) of the roadway surface, determines the left and right edges of the roadway using thermal imaging and determines the centerline of the travel lane in which the vehicle is travelling based on the identified melting agent(s). The system then compares the determined centerline of the travel lane with the actual position of the vehicle and identifies any adjustment needed for the vehicle's position based on the comparison.