This study estimated the number of shopping-disadvantaged older adults and evaluated shopping support policies in Kumagaya City, Japan. Accessibility analysis using an OpenStreetMap road network classified the city into walkable (≤500 m from a food access point) , transit-accessible, and access-difficult zones. Shopping-disadvantaged older adults were defined as non-driving residents of access-difficult zones and estimated by areal weighting. Using projected populations for 2025-2070, we compared existing stores only, stores plus 60 mobile-retail stops, and stores plus 109 public facilities as candidate stops. The walkable share of municipal area increased from 4.2% to 14.8% and 21.6%, reducing the estimated number by 16.0% and 21.5%, respectively, in 2025. Per-location efficiency was initially higher for mobile retail, but the public-facility case surpassed it in 2055. The estimated number peaked in 2040 and declined only modestly thereafter despite the overall population decline. This framework integrates mobile-retail accessibility with future population projections.
