Proximity and Active Accessibility to Urban Green Spaces in Porto Through the Lens of the 15-Minute City

The 15-minute city (15MC) model has gained increasing attention as a framework for promoting sustainable urban living by ensuring that essential services, including urban green spaces (UGSs), are accessible within short walking or cycling distances. UGSs play a vital role in public health, social interaction, and environmental resilience, yet questions remain about how equitably they are distributed and accessed in cities. This study assesses proximity and accessibility to UGSs in Porto, Portugal, through the lens of the 15MC. The methodology combined a GIS-based spatial analysis of walking and cycling catchments with a complementary questionnaire to capture user perceptions and travel behaviors. Results show that, while 84% and 100% of residents live within a 15-minute walking and cycling distance of a UGS, respectively, accessibility remains uneven, particularly for walking. Large peripheral parks contribute significantly to provision but remain less accessible to central neighborhoods, and cycling to UGSs is marginal due to fragmented and insufficient infrastructure, and residual cycling use. Subjective findings mirrored the spatial analysis, highlighting dissatisfaction with cycling conditions and only moderate satisfaction with pedestrian environments. The study emphasizes the need for integrated planning that improves local connectivity, infrastructure quality, and spatial equity to fully realize the 15MC vision.