A route is set by reading map data of an area used for calculating the route. When this area includes a road pricing area, it is determined if there exists a road pricing area into where the user is permitted to enter based on the permission data (road pricing area to where the entrance is permitted and the permission period) read out from an IC card inserted in an ERP car-mounted unit and stored in a storage unit. When there exists a road pricing area to where the entrance is permitted, the road pricing area is excluded from the areas to be avoided, and the route is calculated.