Evolution of Subway Network Systems, Subway Accessibility, and Change of Urban Landscape: A Longitudinal Approach to Seoul Metropolitan Area

The subway is one of the major passenger transport systems in Seoul, Korea. Over the last 30 years, the subway system has interacted with urban land use. This study aims to describe the subway system evolution and reveal the causal relations with land rent and population distributions in conjunction with the evolution of the subway system. Extensive and rapid expansion of subway networks have increased subway accessibility in all regional areas over time and have simultaneously strengthened the status of Central Business Districts (CBDs). These facts indirectly imply a possible strong association amongst land rent, population, and subway accessibility. To reveal these relationships, the Granger-causality test in vector auto-regression form is employed. The results confirm the hypothesis of a causal relationship, the influence of the subway accessibility to the land rent in nearby CBD areas. However, inverse causality also exists between these two variables, implying a more complex relationship. In contrast, population variables have a comparably weak causal relationship with subway accessibility in the spatial context of the subway system in Seoul. Evolution of Subway Network Systems, Subway Accessibility, and Change of Urban Landscape: A Longitudinal Approach to Seoul Metropolitan Area