| 摘要 |
PROBLEM TO BE SOLVED: To utilize the travel routes stored in a route memory device even for road map data of an updated version. SOLUTION: When an update of the version of the road map data is detected, a route corresponding to the stored travel route is retrieved from the road map data of the new version, and the travel route stored in a route memory means is updated to the route expressed by the road map data of the new version of the retrieved result. The travel route stored in the route memory means can be utilized even for the version-updated road map data, the labor and time for newly storing a travel route can be omitted, and operability can be improved. |
