OPTIMUM AND ALTERNATE ROUTE CALCULATIONS FOR IN-VEHICLE NAVIGATION SYSTEM

The optimum route calculation has recently become an element of primary importance for in-vehicle navigation systems that have a route-guidance function. The one optimum route, though, calculated by in-vehicle navigation systems is not always the best way for the driver due to ever changing traffic conditions. If the system shows alternate routes, drivers can select the best route by themselves. The authors of this paper have developed a method of calculation to get one optimum route and several alternate routes, which is accomplished by exchanging coefficients of link-cost for alternate route calculations using the data of first-calculated optimum route. This paper describes a means of calculating for some alternate routes and the evaluation result of alternate route calculation.