This study investigates spatial justice in convenience store accessibility by examining how travel modes, mobility conditions, and spatial structures jointly shape service equity. Drawing on the “capability space” framework, it first constructs a behavior-based accessibility measure using the Three-Step Floating Catchment Area (3SFCA) method and credit card transaction data, capturing individuals’ actual ability to access retail services. This empirically grounded indicator is then analyzed alongside socio-spatial and demographic variables to uncover disparities rooted in capability differences and institutional structures.

Owing to Jongno-gu’s compact urban form, walking showed the highest equity. In contrast, cycling and driving revealed pronounced gaps in accessibility, which is attributable to uneven resource allocation and transportation infrastructure. While walking provides relatively equitable access overall, it does not serve older adults and residents living in peripheral neighborhoods. Infrastructural discontinuities and mode-user mismatches constrain cycling accessibility, whereas driving expands spatial coverage but reinforces structural advantages for car-owning households. These findings underscore how transport modes, land use patterns, and population characteristics interact to produce unequal service landscapes.

Accordingly, this study presents an integrated framework that operationalizes spatial justice through behavior-based accessibility assessment. By connecting actual service use with socio-spatial disparities, it enables targeted diagnosis of capability inequalities in retail provision. Beyond methodological contribution, the findings offer actionable insights for equitable and inclusive mobility planning in dense, aging urban contexts