Lane hogging prevention system

The present invention provides a lane hogging prevention system enabling prevention of lane hogging even when a vehicle, such as an AHS (Advanced-cruise-assist Highway System) car (2) is running on a road under bad weather conditions such as rainfall or snowfall or in a dangerous section at a relatively high speed, and this lane hogging prevention system comprises a vehicle (2) equipped with a vehicle position detection sensor (8), a vehicle state detection sensor (4) for detecting a running speed, an on-vehicle processing unit (5), a vehicle control unit (6) for controlling a running speed and a steering angle of the vehicle (2), and an alarm device (7); and on-road facilities including a plurality of position detection support facility (11), a road surface situation detection facility (16), an on-road database (13) for storing therein road line form information, and a road-to-vehicle communications facility (14). In this system, a specified zone up to a dangerous section such as a sharp curve where high speed running is dangerous is regarded as a service area, a service-in position detection facility (11a) is installed at a position away by a specified distance from an entrance of the dangerous section, also a service-out position detection facility (11b) is installed at a position near an entrance of the dangerous section, road surface information processed by the on-road processing facility is integrated with data on a current position and a current running speed of the AHS car (2), and controls are provided based on the integrated information for prevention of lane hogging.