Access = how close, dense, and varied nearby services are (groceries, pharmacies, schools, healthcare, parks, transit), computed from real OpenStreetMap data along the actual walkable street network.
Connectivity = how well-knit the street network itself is nearby — how many intersections you can actually reach on foot within about 15 minutes, not just straight-line distance.
Replicates the accessibility & connectivity method from Lai et al.,
"Understanding the interplay between urban segregation and accessibility to services with network analysis," PLOS ONE, April 2026, applied here to Chicago for the first time — the original study covered 92 cities, not including Chicago. Income from Census ACS 2023 via the Chicago Data Portal. Community area boundaries and 15-minute walksheds built from OpenStreetMap.