Quantitative analysis of future changes in regional public transport coverage in Hokkaido municipalities

Abstract

To support the restructuring of sustainable regional public transport under population decline, this study cross-sectionally applied a spatial analysis method using future population projections and GIS to 182 municipalities in Hokkaido. We quantitatively analyzed future changes (2025–2050) in the "public transport coverage rate," defined as the proportion of the population residing within walking distance of transit services. A macro-level analysis across Hokkaido confirmed an upward trend in the coverage rate. This reflects the structural characteristics of the projection data, wherein relative population concentration occurs due to preceding depopulation in suburban and sparsely populated areas. On the other hand, a micro-level analysis by municipality demonstrated that some areas exhibit decreasing or stable coverage rates, contrary to the overall macro trend, and structured how differences in the "initial spatial structure" formed by regional characteristics—such as local industries, topographical conditions, and urban scale—influence the future transition patterns of the coverage rate appearing in the projection data. The comprehensive cross-sectional comparison and categorization presented in this study can serve as foundational insights for practicing EBPM and establishing sustainable public transport tailored to regional characteristics.