To obtain own vehicle information such as a position, a travel state, and the like of an own vehicle, the information input unit 8 is connected with various kinds of sensors, communication equipment for communication with the outside, and the like mounted on an own vehicle. For example, to accurately ascertain a position of the own vehicle, the information input unit 8 can receive, from a global positioning system (GPS), signals and image data transmitted from a satellite orbiting the earth or receive information through road-to-vehicle communication with an antenna or a communication chip mounted on a road.