Route guidance system, route guidance server apparatus and navigation terminal apparatus

A navigation terminal apparatus (5) includes: terminal map data (515); a route search means for searching for a traveling route, through which a mobile object (4) is to travel, based upon a specific search condition pertaining to a travel cost; and an updating means for updating route data expressing the traveling route by replacing a first road link group making up a route segment accounting for at least part of the traveling route with a second road link group making up another route segment, with a start point and an end point thereof matching the start point and the end point of the route segment accounting for at least part of the traveling route. The another route segment is included in route information obtained from the external apparatus (6); and the route data include position reference data pertaining to positions of all road links constituting the traveling route and cost data pertaining to travel costs of all the road links.