| 摘要 |
<p>PURPOSE:To attain smooth transition between hierarchies in a multi-hierarchy route search. CONSTITUTION:A route searching part 14 executes a route search to the destination inputted from an input part 10 by utilizing data of a road network data storage part. At the time of data expansion from each intersection, in the case both intersections of a superordinate hierarchy and a subordinate hierarchy are connected with regard to the same connecting road, the data is expanded to the intersection of the superordinate hierarchy, and in the case of a road to which only the intersection of the subordinate hierarchy is connected, the data is expanded to the intersection of the subordinate hierarchy only in the case the original intersection is not one which connects the superordinate hierarchy and the subordinate hierarchy. Accordingly, the transition to the road of the superordinate hierarchy is executed automatically and a route search can be executed.</p> |
