Route searching apparatus for vehicle.

摘要

A route searching apparatus finds the optimal route between 2 points on a road map by searching on a first hierarchical level for a main road using a first cost-function (favouring e.g. wide roads) and subsequently searching on a second or even third hierarchical level for routes connecting the start and end points to the main road using second or third cost-functions (favouring e.g. shorter driving distance). Alternatively, the total distance between start and end points may be divided in e.g. 4 parts, the search in the central parts favouring wide roads and the search in the start and end parts favouring shorter driving distance. <IMAGE>