The evaluation of road pricing for the Tokyo metropolitan area with respect to the environment

The Tokyo metropolitan area is currently suffering from massive traffic jams that promote Nitrogen Oxide (NOx) air pollution. Hence the Tokyo metropolitan government is considering the enforcement of 'road pricing' as one of the policies of Transportation Demand Management (TDM). Four kinds of pricing-boundary schemes proposed by the Tokyo metropolitan government are considered. It is expected that air pollution would partly deteriorate just beyond the pricing boundary due to detouring traffic but that would gradually improve. It's necessary to consider such environmental deterioration when enforcing road pricing albeit the research is not complete. Hence the purpose of this study is to quantitatively evaluate such environmental deterioration. The present traffic condition was represented by the traffic simulator VISUM/DYNEMO that includes the fluid traffic-flow model which is effective for reproducing the heavy traffic flow in macro scale network such as the Tokyo Metropolitan Area. The traffic-simulation model was then verified by comparing the simulated and observed traffic volumes. Finally, we evaluate the total improvement and the partial deterioration due to road pricing. This study determined which pricing-boundary scheme is the best with respect to the impact of detouring vehicles.