Vehicle-mounted device, traffic-information acquisition method, traffic-information provision system, and traffic-information provision method

摘要

When a change occurs between a previous traffic condition based on traffic information provided previously and the current traffic condition, a control unit of a vehicle-mounted device performs control such that traffic information is acquired from an external device via wireless communication. A comparison of current vehicle traveling conditions and previous vehicle traveling conditions can also be used to determine whether traffic information should be updated.