Devices, methods, and programs update map information stored in a storage medium based on map update information distributed from a map distribution center. The devices, methods, and programs search for a vehicle route based on the stored map information, perform first guidance along the route, and identify a target area on the route that will be updated when the map information is updated. The devices, methods and programs determine whether the update of the target area will be complete when the vehicle reaches the target area. If the update of the target area will not be complete when the vehicle reaches the target area, the devices, methods, and programs request second guidance for the target area from the map distribution center, switch from proving the first guidance to providing the second guidance through the target area, and return to performing the first guidance when the vehicle exits the target area.