Walkability analysis of Sofia's neighborhoods powered by 15-minute city concept

Urban walkability and accessibility are essential for sustainable urban development, affecting public health, environmental quality, and social cohesion. Points of Interest (POIs) like parks, schools, and health services play a key role in making urban areas pedestrian-friendly, especially when located near residential buildings. This study applies the 15-minute city concept and introduces an Accessibility Index that evaluates residential access to POIs, incorporating diversity metrics such as the Shannon and Simpson indices. The sidewalk infrastructure and pedestrian network connectivity are accessed using weighted POIs to measure walkable access. By defining a sustainable urban environment in terms of accessibility, POI richness, and evenness, the study delivers a robust tool for assessing the compliance of urban neighborhoods with the 15-minute city concept. Applied to Sofia's Lozenets district, the study examines 4000 POIs grouped and weighted based on their usage. GIS analysis calculates proximity, revealing significant differences in accessibility between neighborhoods, with better-planned areas showing stronger walkability. Results show significant differences in accessibility and diversity between different neighborhoods in the district, with less developed and newly built areas lagging behind more thoroughly planned and well-managed parts of the city where space for public infrastructure is well planned, distributed, and developed. The findings highlight the significance of thoughtful urban design and planning in fostering environments that encourage walking as a viable and preferred mode of mobility.