A route searching section 33 determines whether the area of the current position is an urban area or a suburban area, sets a predetermined area S or a predetermined time t responsive to the determination result, and determines the presence or absence of restriction on each time restriction road depending on whether or not a time restriction road exists in the predetermined area S centering around the current position and whether or not the restriction time period of the time restriction road overlaps the time period in the predetermined time t from the current time to. If the route searching section determines the presence of restriction, it searches for a route avoiding the time restriction road.