NAVIGATION SYSTEM, METHOD THEREFOR, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To make accurately determinable that a vehicle has strayed from a route during guiding of the vehicle along the route, based on a list of guide points. SOLUTION: In response to a request from a navigator 101 held in a vehicle, a route searching center unit 102 transmits a list of guide points as a result of route search from a departure point to a destination. A guide control means 106 of the navigator 101 outputs guide information at a guide point to a guide information output means 109. A route deviation determining means 107 obtains an elliptic region with focuses at guide points just before and after passing and a major axis equal to the distance between both guide points and, if the present position goes away out of the elliptic region, determines that the vehicle has strayed from the guiding route.