Patent ID: 8473201

Claim:
A current position determining device, comprising: current position detection means which detects a current position of an own vehicle; storage means which stores: map information including road configuration information identifying a configuration of a road, and road type information identifying a type of the road; and branch position information identifying a branch position of a road contained in the map information; current position estimation means which estimates, using the map information, an estimated current position corresponding to the current position of the own vehicle detected by the current position detection means; detection range identification means which identifies, based on information on a road at the each branch position, a range for detecting a traveling direction of the own vehicle, as a detection range; lane change detection means which detects, when the estimated current position of the own vehicle detected by the current position estimation means is included in the detection range identified by the detection range identification means, whether the own vehicle has changed lanes; and estimated current position correction means which corrects the estimated current position estimated by the current position estimation means, using the information on the lane change detected by the lane change detection means wherein: the detection range identification means is configured to: acquire, from the storage means, road configuration information on a road to which the estimated current position belongs; and identify the detection range when the road to which the estimated current position belongs branches into roads having a Y intersection configuration; and the lane change detection means detects the lane change when the road to which the estimated current position belongs branches into roads having a Y intersection configuration; and when the detection range is not identified in the branch position, the detection range identification means identifies the detection range according to the road type of the road to which the estimated current position belongs, a speed limit, and a parallel extended distance across which the branching roads extend in parallel.