To perform practical route search capable of flexibly avoiding a useless detour in order to cross a road.

In a route search system for a pedestrian, links located on both sides of a road are previously related with each other as a pair. In route searching, a route is searched under a condition that a road can be crossed on an arbitrary position between links set as a pair. Namely, even in a place where links for crossing are not previously set, a perpendicular is drawn from one link to the other link and a virtual node LVe is set on the other link to generate a virtual link. When searching a route from a starting point ST to a goal GL, a route RT2 passing the virtual link can be obtained and a route avoiding a useless detour such as a route RT1 through pedestrian crossings can be searched.