There are several problems remaining to assure the practicality of the route calculation logic structure of a Dynamic Route Guidance System (DRG) to keep actual usefulness. For example, with the method that adds up link time data for the entire route from origin to destination, forecast time data values for the links ahead are necessary. It must be necessary to avoid a very long and circuitous route on the basis of only partial detour considering the jam ahead. In order to gauge the effectiveness of DRG in shortening travel time, it is necessary to consider an area's characteristics; the difference of the road network structure, the areas with excess road capacity relative to the traffic volume, and the areas without excess capacity. How to evaluate the DRG route is also a big issue. In this paper, the authors set forth ideas on the structural criteria for DRG route-calculation logic from the point of view that a driver's requests for route selection occur at "choice points" where roads intersect and are thus also highly dependent on the characteristics of the road network. In their study, they used the characteristics of the road network in Aichi Prefecture and link travel time data provided by optical beacons, and they make clear the effectiveness of DRG with regard to the characteristics of the local area.
Abstract