MAP DATA PROCESSING APPARATUS AND METHOD, AND MAP DATA PROCESSING SYSTEM

On a vehicle side, map data storage section stores map data, which is to be updated by using the latest map data transmitted from an information center. The map data includes map data of a number of types, such as landmark information, drawing data, route calculation data. For drawing data and route calculation data, the information center sends differential data indicative of difference between the latest data held by the center and the map data held by the vehicle. The differential data of the drawing data is stored separately from extant data in the storage section by generating processing section. The differential data of the route calculation data is combined with extant data by restructure processing section to thereby restructure route calculation data. On the other hand, for landmark data, the center transmits full data, which is data corresponding to the entire latest map data, rather than only the difference. The full data is used to overwrite the extant data. As described above, an appropriate update process is performed according to the type of map data.