Advanced Cruise-Assist Highway Systems (AHS) are expected to solve various road traffic problems such as traffic accidents and congestion, and research is being actively promoted toward the introduction of these systems. One of the key technologies needed for AHS is "technology for detecting road surface conditions", or technology which recognises road surface conditions (dry, wet, snow-covered, frozen, etc.) using sensors. In research and development on technology for detecting road surface conditions thus far, laser radar and various other sensor devices have been proposed, and the feasibility of their application has been investigated. On the other hand, large numbers of cameras have already been installed for monitoring operations by road controllers. If software-based functions for detecting road surface conditions can be achieved using these cameras as the sensors, then AHS can be introduced quickly and with low cost. This paper presents principles for detecting road surface conditions using cameras which are shared with other applications, confirms the appropriateness of these principles through tests using these principles, and examines problems remaining for implementation. In addition, the paper also presents policies for solving these problems, and investigates the degree to which such a system might approach the practical level.
Abstract