A communications-type car navigation system including a vehicle-mounted terminal
and a server. When transferring, to the terminal, the result of a route searching
which the server has performed, the server transfers the data that will satisfy
the requirements of a route guiding method which the user wishes. Also, the server
transfers the route data that has been compressed. Concerning the map data as well,
the server transfers only the necessary attributes thereof. Moreover, the following
conditions allow the operability to be enhanced: the selection of a map transferring
method and the route guiding method where the driving state has been taken into
consideration, and the selection of a guiding unit which the user wishes.