Changhyo Yi

Assessing the spatial equity of Seoul’s public transportation using the Gini coefficient based on its accessibility

ABSTRACT The purpose of this research is to develop a methodology for calculating the index of the spatial equity for the public transportation services for the city of Seoul using the Lorenz curve and Gini coefficient based on accessibility to the services. The index was estimated for 100 m × 100 m cells first and then aggregated for 424 traffic analysis zones (TAZs) in the city. The indices for Seoul’s subway and bus were represented with and without the weighting factor. On the basis of this methodology, this study assessed the effect of an additional subway line on the spatial equity before and after its operation. Furthermore, an index of relative difference indicating the change in population and employment in the station areas was applied to investigate the changed effects of spatial equity between population and employment from the new subway line. The core findings from this research are summarized as follows. First, the subway network of Seoul provides more unequal public transportation services for the TAZs than for the bus network. Second, an improvement in the operation frequency of both transit modes would deepen the spatial inequity of Seoul. Third, a subway extension plan for Seoul could noticeably reduce the spatial inequity. The plan would improve the spatial equity for the population more than that for employment. The most important meaning of this study is to be found in combining spatial equity on the supply side with transit-oriented development (TOD) on the demand side. So, by establishing a TOD policy for the additional subway station areas, an appropriate land-use pattern can be established for maximizing potential ridership in consideration of the combination.

Relationship Between the Formation Conditions and Durations of One-Person Households in the Seoul Metropolitan Region

Rapid demographic changes have occurred in Korea, with the number of one-person households almost doubling between 2000 and 2010 in the Seoul metropolitan region. Developed countries experienced these changes previously through the so-called second demographic transition. The purpose of this article is to ascertain how both the socioeconomic attributes and the location characteristics of one-person households at the time of their formation affect the durations of these households under the rapidly changing Korean demography. The spatial distribution of the areal location quotient indexes for one-person households indicated that the concentration of these households is relatively higher in the inner cities of metropolitan areas and the outskirts of the Seoul metropolitan region. Meanwhile, the distribution patterns of the relative concentration levels for one-person households by age group exhibited obvious differences. In the survival analysis for the entire sample of this research, household attributes were the primary determinants. However, the results of the empirical analyses by age group indicated that location characteristics were significant as well, although the significance of the variables varied with the types of one-person households. The duration of households of one person under 40 years old was affected by their access to employment districts and the concentration level of one-person households in the area. In contrast, the duration of households of one person 65 years old and older was influenced by the distribution of affordable housing. The findings of this study provide a framework that is able to make sense of the changing characteristics of the one-person households of nations in transition from developing to developed countries.