Providing traffic information to drivers and realizing the DRGS (Dynamic Route Guidance System) by using in-vehicle information equipment and communication infrastructure are proposed as one of the user services in Japan. One of the purposes of the user service is environment protection. In this paper, the authors estimated the environmental impacts of such traffic control systems. The macroscopic simulation model which can describe the traffic flow on a large road network dynamically is used for estimating the traffic flow. That simulation model can represent 2 patterns of traffic flow; one case is that drivers select the shortest route to their destination and the other case is that drivers select the alternative route which is recommended by DRGS. In this experiment, an original parameter "acceptance ratio" is defined and it expresses the ratio of the drivers who can get the information from their in-vehicle information equipment and accept the recommended route. Tokyo Metropolitan Expressway is taken as a model and the amount of CO2 which is emitted by each vehicle is investigated. As a result, with DRGS the traffic flow in the network was equalized and the average velocity of vehicles became higher because each vehicle hated the crowded route. According to these results, it is shown that providing real time traffic information to drivers and DRGS have a benefit in traffic management and reduce CO2 and NOx emissions.
Samenvatting