In a conventional map distribution system, a mobile terminal which is a map information terminal sends road shape data to a center server which is a map distribution server, and the center server updates map information stored in a map database by using the road shape data sent thereto (for example, refer to patent reference 1).
In another conventional map distribution system, when a vehicle driven by a user of a map information terminal travels along a road which does not exist in the map data held by the map information terminal, the map information terminal transmits the traveling path of the vehicle to a center server, and the center server updates the map information of the map database held thereby according to the traveling path. After that, according to the circumstances, the center server distributes difference data which the center server has created according to the map information of the updated map database to the map information terminal (for example, refer to patent reference 2).
Even any of the above-mentioned map distribution systems can distribute map data which the user desires as difference data to enable the map information terminal owned by the user to acquire the distributed difference data when the map information of the map distribution server is correctly updated on the basis of data about the traveling path of the vehicle and when there are data about a traveling path which were acquired when someone actually traveled along the road once.