NAVIGATION SYSTEM, NAVIGATION PROGRAM, RECORDING MEDIUM, AND HIGH-SPEED ROAD INFORMATION FORMING METHOD

摘要

PROBLEM TO BE SOLVED: To search a route comprising a high-speed road which is easy to run and can be passed at a higher running speed when a car runs in reality, on the basis of factors which influence easiness in running and a running speed, when a route is searched. SOLUTION: A navigation system has a storage portion which stores search data including high-speed road information for distinguishing high-speed roads, a high-speed road determination portion which determines whether or not a road is a high-speed road on the basis of the high-speed road information, and a route search portion which searches a route lowering a searching cost for a road determined as a high-speed road, and searches a route which minimizes the searching cost. COPYRIGHT: (C)2004,JPO