Patent ID: 8510027

Claim:
A vehicle traveling position judging method for judging a traveling position of a preceding vehicle, comprising: a relative position information acquisition step of acquiring relative position information of the preceding vehicle and a host vehicle at a predetermined point in time; a host vehicle traveling trajectory information acquisition step of acquiring traveling trajectory information of the host vehicle after the predetermined point in time; and a preceding vehicle position judging step of judging a traveling position of the preceding vehicle on the basis of the relative position information and the traveling trajectory information of the host vehicle, wherein in the relative position information acquisition step, the relative position information is calculated on the basis of a difference between coordinate information of the preceding vehicle acquired by a GPS and coordinate information of the host vehicle acquired by a GPS, a lane change information acquisition step of acquiring lane change information regarding lane changes of the preceding vehicle after the predetermined point in time is further included, in the host vehicle traveling trajectory information acquisition step, host vehicle passage information indicating that a traveling trajectory of the host vehicle after the predetermined point in time has passed a same lane judgment region, which is virtually set at the position of the preceding vehicle at the predetermined point in time, or a judgment end line, which is virtually set ahead of the same lane judgment region, is further acquired, in the preceding vehicle position judging step, the traveling position of the preceding vehicle is judged on the basis of the lane change information and the host vehicle passage information, and in the preceding vehicle position judging step, it is judged that the preceding vehicle at the predetermined point in time is in the same lane as the host vehicle after the predetermined point in time, when the host vehicle has passed through the same lane judgment region, and that the preceding vehicle at the predetermined point in time is in a different lane than the host vehicle after the predetermined point in time, when the host vehicle passes through the judgment end line without passing through the same lane judgment region.