地方都市の代表交通におけるLRT導入影響評価: 岡山県岡山市・総社市を例として

摘要

日本の多くの地方都市では，モータリゼーションの進展により市街地が郊外へ拡大し，公共交通のサービス水準の低下を招き，さらにモータリゼーションの進展に繋がるというまちづくりにおける負のスパイラルが発生している．このような状況を打破するために，新たな公共交通として高い走行性能や安価な建設コストが特徴のLRT（Light Rail Transit）が注目されている．%Recently, LRT attracts attention as a new public transportation in many provincial cities in Japan because of the high driving performance and low construction cost. However, the changes in traffic flows by the introduction of LRT are not well evaluated as a principal traffic of provincial city. In this paper, we develop a public transportation network model including existing railways and buses for the area including Okayama and Soja city to evaluate the above effects. The network model contains 74 nodes, 234 links, 16682 routes and 5402 0D before introducing LRT and it contains 74 nodes, 282 links, 20591 routes and 5402 0D after introducing LRT. We employ system optimum assignment, user equilibrium assignment and stochastic user equilibrium assignment model. We find that (1) the stochastic user equilibrium assignment is suitable for the urban area and (2) that the system optimum assignment is suitable for the suburb area. (3) Scheduled speed and frequency of trains are the key factors.