Studies are underway to further the research on Advanced Cruise-Assist Highway Systems (AHS) and to advance the practical application of such systems for realization of safe road transport. AHS systems are made up of a variety of safety support services, and one of these is the support service for prevention of lane departure. This service detects the lateral position of the vehicle in the lane with high accuracy in order to keep the vehicle from straying outside the lane. Its purpose is to reduce the number of serious accidents that occur when inattention, drowsiness, or other such causes result in lane departure. It is considered desirable for this service to be usable in a variety of meteorological conditions, road structures, and topographical conditions. A number of different technologies are available for accurate position detection. The global positioning system (GPS) is not sufficiently capable of acquiring satellite signals inside tunnels, on the lower level of multi-level roadways, in mountainous areas, and so on, where its position detection accuracy is degraded. Devices for optical sensing of white lane lines cannot guarantee operation in fog, rain, and other such weather conditions, in snow cover, during flooding, and so on. The lane marker system is a position detection system that operates stably without being affected by these environments, and the utilization of a lane marker system will enable provision of the lane departure prevention service under a variety of conditions. It is desirable for this service to have lane markers installed closer together in order to extend the detection range laterally and longitudinally for enhanced controllability. From the point of view of infrastructure cost reduction, however, it is desirable to install fewer lane markers. This project studied the detectable width, the installation interval, the position detection accuracy, and other such lane marker system specifications from the points of view both of service provision and of infrastructure cost reduction. Road tests were also conducted using lane markers buried in a roadway and a vehicle equipped with a detector. The tests evaluated such parameters as detectable width, installation interval, position detection accuracy, vehicle speed, heading angle, and so on. The installation specifications required for service provision were subjected to verification, and those results will be reported here.
Samenvatting