To enable judgment whether or not a driver's own vehicle will come in contact with an object with an overhang even when a traveling expected locus enters an lower part of the object with an overhang.

Out of a plurality of images taken by a CCD camera in moving of the driver's own vehicle, and a movement amount of the driver's own vehicle calculated based on a steering rudder angle signal detected with a steering angle sensor and a speed signal detected with a combination meter (S16), nodes are matched between images of each group (S17), as well as three dimensional location data of matched nodes are calculated, projected on the three dimensional map and stored (S18). Afterwards, whether the object exists or not in the travel expected locus of the driver's own vehicle is judged.