Analysis of Regional Disparities in Public Transportation Accessibility: A Spatial Approach to Equal-Time Job Accessibility

Abstract

This study empirically analyzes regional disparities in public transportation service levels between the Seoul metropolitan area and other South Korean regions, offering policy implications for balanced national development. Overcoming prior research limitations like reliance on administrative boundaries or a single-transportation mode, this study utilizes nationwide direct-link transit data to evaluate mobility and accessibility at a fine 500m × 500m grid cell resolution. Mobility is defined as reachable grid cells and accessibility as accessible jobs, both within one hour. Analysis reveals the Seoul metropolitan area and Busan-Ulsan-Gyeongnam have the highest mobility and accessibility, while Gangwon ranks lowest. Notably, dense industrial clusters show high public transport job accessibility, underscoring that improving transit access to employment centres, not just attracting businesses, is key to enhancing regional competitiveness.