15-Minute City Failures: Why Proximity Planning Misses the Accessibility Gap
Objective
Assess whether 15-minute city implementations have meaningfully reduced mobility inequality or primarily benefited already-accessible urban cores.
Methodology
Cross-city analysis of 15-minute city pilot programs in Paris, Melbourne, and Portland. Accessibility scoring using isochrone mapping against income quintiles. Transit and walking infrastructure data from OpenStreetMap and municipal datasets 2020-2025.
Findings
15-minute city planning has disproportionately benefited higher-income neighborhoods. Low-income peripheral areas remain underserved: Paris data shows bottom income quintile has 40% fewer amenity types within 15-minute walk than top quintile despite formal designation. Melbourne pilot improved walkability scores by 22% in inner suburbs but only 6% in outer ring. Root issue: planning targets proximity of amenities, not affordability or quality within that radius.
Key Assumptions
- •Amenity proximity is a reasonable proxy for accessibility
- •Income quintile data is representative across study cities
Limitations
- •Study limited to three cities
- •Cultural differences in walking behavior not fully controlled