| 摘要 |
PROBLEM TO BE SOLVED: To reduce a time for downloading road information and communication expenses for a radio communication means by reducing the amount of road information to be downloaded via the radio communication means depending on a vehicle travel route. SOLUTION: This on-vehicle navigation device 1 comprises a position detecting means 2 for detecting position formation for a vehicle, a road information requesting means 10 for requesting the road information for the position information to a server via the radio communication means, a display means 7 for displaying the road information received from the server 15, and a road determining means 4 for determining from the detected position information whether the vehicle is located or not on a predetermined road with no crossing. The road information requesting means 10 reduces the amount of the received road information by requesting only the road information relating to the predetermined information to the server 15 when the road determining means 4 determines that the vehicle is located on the predetermined road. COPYRIGHT: (C)2004,JPO |
