Multimodal Accessibility and Spatial Equity of Public Activity Facilities for Children and Adolescents in Wuhan, China: Implications for Socially Sustainable Urban Planning

Background: Equitable access to public activity facilities for children and adolescents is an important dimension of social sustainability and sustainable urban mobility, yet evaluations based on static distance or a single travel mode may misrepresent service opportunities. Methods: Using Wuhan as a case study, we constructed 600 stratified community demand points representing approximately 1.90 million residents aged 5–19 years and evaluated 180 facilities. Baidu Maps navigation times for walking, weekday after-school door-to-door public transit, and driving were incorporated into a truncated Gaussian two-step floating catchment area model. Population-weighted coverage, inequality, spatial clustering, and supply–demand mismatch were assessed, with sensitivity tests for supply weights, age composition, demand definition, and route-time uncertainty. Results: Within 30 min, population-weighted coverage was 37.85% for walking, 28.44% for public transit, and 94.20% for driving. Wider time thresholds reduced weighted Gini coefficients but did not eliminate positive spatial clustering. Under the 60 min public-transit scenario, four peripheral districts contained 78.00% of the high-demand–low-service proxy population; their combined share remained 80.34% when demand was defined by population density, although classification of individual units changed. Accessibility rankings were stable under supply-weight and age-group sensitivity tests, while repeated driving observations revealed threshold-crossing uncertainty. Conclusions: Broad driving coverage cannot substitute for neighborhood-scale walking and public-transit opportunities. The framework provides an auditable tool for monitoring the spatial inclusiveness of public services and identifying priorities for facility infill and first/last-mile improvements, thereby supporting socially sustainable urban planning. The results represent potential service opportunities rather than actual travel behavior, facility use, or a comprehensive assessment of social equity.