When a driving assistance system of a navigation device in a subject vehicle is able to communicate with a cooperative remote driving assistance system in an oncoming vehicle, images are obtained from individual front monitor cameras of the subject vehicle and the oncoming vehicle. These obtained images are exchanged. From within these images, common objects are recognized to thereby compute a positional relationship between the subject vehicle and the oncoming vehicle. The computed positional relationship is then shown in a display unit by a vehicular model using an outline of a top view of a vehicle. Consequently, a driver can intuitively recognize the positional relationship between the subject vehicle and the oncoming vehicle by seeing the display unit.