An Evaluation of the Effect of Railway Abolishment on the Traffic of the Surrounding Roads and the CO₂ Emissions

Abstract

Railway is an environment-friendly transportation system and important for a low-carbon society. However, the deficit-ridden railway lines have been abolished and replaced with other transportation modes. The benefit-cost （B/C） analysis has been used as the criteria of abolishment, however, it is not favorable from the perspective of the effect on the surrounding roads or right to transport. In this work, authors presented the new criteria of social significance evaluation of the railway lines by the calculation of the change of traffic caused by abolishment, and economic / environmental impact. Authors investigated the change of traffic and CO₂ emissions in the surrounding roads by the abolition of railway lines. And authors compared the railway deficit and road improvement costs. These estimations were applied for 2 abolished lines and 13 existing lines with low management stability. In the case of 2 abolished lines, the traffic congestion didn’t change if 80% of passengers converted to passenger cars. These results agreed well with the actual situation after the abolition. In the case of the existing 13 lines, 7 lines will cause the traffic jam by their abolition, and 6 of them cause heavy traffic jam. The railway deficit of these 6 lines are smaller than road improvement costs of surrounding roads. The CO₂ emissions can be reduced by the railway operation except ASA Seaside Railway with smallest number of passengers in Japan. These results suggest that above a certain number of passengers is required to reduce the CO₂ emissions by railway operation, and the reduction ability of CO₂ emission have weak correlation with management stability. Through this work, it is suggested that the independent evaluation of the change of traffic and economic / environmental impact can be the new criteria of the railway lines’ social significance.