For example, JP-A-2006-327346 discloses a conventional art to set a traveling allowable range from the present position of a vehicle to a destination and to impose regulation on traveling of the vehicle when the vehicle deviates from the traveling allowable range while the vehicle is traveling.
It is noted that, the above-described conventional art is unable to cause a driver of the vehicle to notice that the vehicle has deviated from the traveling allowable range, unless regulation is imposed on traveling of the vehicle when the vehicle deviates from the traveling allowable range. In addition, even when the driver notices that the vehicle has deviated from the traveling allowable range erroneously and tries to return the vehicle into the traveling allowable range, the above-described conventional art is unable to cause the driver to return the vehicle into the traveling allowable range promptly, since the regulation is already imposed on traveling of the vehicle.