| 摘要 |
PROBLEM TO BE SOLVED: To provide an on-vehicle navigation system which guides a car to an appropriate road by judging whether a to-be-opened road, seasonally closed road, etc., are currently opened or not. SOLUTION: In a DVD-ROM where map data is stored, a scheduled open date is recorded as effective-period information together with the data of to-be- opened road. In addition, together with the data for seasonally closed road, an open period is recorded as an effective-period information. A navigation system main body 10 detects a current date/time from a GPS receiver 3. Then, the map data around a car is read out to a map buffer 11, to be compared to the effective-period information and current date/time, so that the road data is effective or not is judged. If effective, the road, for example, is displayed on a display device 7, and if not effective, that is not displayed on the display device 7. |
