社会実験による道路料金政策の評価

抄録

Although road prices, including taxes and various other charges that are levied on road users, have been sources of finance for road construction and maintenance, they have recently been expected to serve as a tool for Transportation Demand Management (TDM). Congestion road tax, for example, has been introduced in several cities, including London, to shift the transportation demand to uncrowded roads or off-peak periods. In order to successfully introduce road pricing, it is important to understand the price elasticity of transportation demand and its effects in alleviating road congestion and environmental burdens. Therefore, social experiments on road pricing are conducted to collect data unique to a particular city.

This study aims to review the road pricing principles, including marginal and average cost pricing, and their policy implications; further, it aims to conduct a case study to compare the purposes and designs of social experiments on road pricing policies in Japan and the United States. Finally, it concludes that experimental design is the key to control pricing conditions and collect individual data of road users' travel behavior in order to effectively evaluate road pricing policies.