Evaluation of urban structure for more effective use of regional subway network

The paper reports on a research to conduct a measurement of the regional accessibility of the Seoul Metropolitan Subway in Korea with respect to its network topology and the spatial distribution of land uses in the urban region as well as in each catchment area of the subway stations seeking for its more effective use. This research assumed that the stagnated use of the subway is due to regional imbalance between the jobs and the residences located in the catchment areas. Therefore, the regional accessibility of the Seoul Metropolitan Subway in terms of work trips was represented by the amounts of population and employment which can reach a station from all other stations of the network. The difference between the two accessibility indicators means the rate of jobs-housing imbalance in the catchment areas of the subway. An accessibility measurement model developed using raster GIS technique disaggregates population and employment of the catchment areas into numerous tiny raster cells and determines the network travel times between the raster cells using a time-oriented minimum-path algorithm. The model represents the both accessibility indicators for a cell after calculating the amounts of population and employment as a function of travel time.