| 摘要 |
PROBLEM TO BE SOLVED: To seemingly shorten processing time for route searching, by starting route searching for the neighborhood of a given spot based on link connecting information even before the starting of route searching is instructed. SOLUTION: Once an operator sets spots such as starting position, through position, or destination, the device starts a precedent route searching process for the neighborhood of these spots even before starting of route searching is instructed. During the idle time after the operator sets position such as destination until the operator instructs the starting of route searching, the device can perform the route searching process in advance, and therefore, apparent processing time for route searching is shortened. When an operator changes the destination or the through position after the precedent route searching process is started, the process is stopped. When the result has been derived the result may be discarded. |
