抄録
The purpose of the paper is to analyze the traffic congestion in the mass transportation system in Tokyo Metropolitan Area. An econometric model was constructed to explain the changing trends of distancial distributions of population, employment, production, land price and traffic to Central Business District, and estimated by the pooling data of 6 subareas and 7 years. The simulation showed a continuous tendency of double-ring growth pattern of suburb area, and increasing traffic congestion to the future. The analysis also revealed that the social cost caused by traffic congestion reached to 1.1 billion yen for 137, 000 persons. This social cost is estimated to increase to 4.6 times in 1970-80 based upon real wage increase, increase of congestion, increases of traffic time and traffic population. The benefit-cost ratio of past transportation investment was revealed as quite high based upon the analysis which suggested that the initial investment was covered by 12 years using 10 percent of discount rate. The analysis also revealed the inverse effects of transportation investments to increase the transportation capacity and to shorten the traffic time upon the velocity of urban sprawl. The analysis as a whole strongly suggests the urgent needs to improve the mass transportation system to mitigate the accelerated congestion in the future.
