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.