Every planner has that moment, the one where a map doesn’t just show you where things are, but why they are the way they are. For me, that moment came when I first saw a redlining map.

THE MAP

It was a digitized version of a 1930s-era Home Owners’ Loan Corporation (HOLC) map, color-coded to show where the federal government recommended (or warned against) lending money for home purchases.

THE LEGEND

- Green = “Best” (aka white, affluent, low-density neighborhoods)
- Blue = “Still Desirable”
- Yellow = “Definitely Declining”
- Red = “Hazardous” (aka predominantly Black, immigrant, or working-class areas)

WHAT HIT ME

These weren’t just colors on a map. They were policy decisions,  encoded into neighborhoods. They shaped where wealth accumulated and where disinvestment took hold. They influenced school funding, health outcomes, transit access, and so much more.

And the kicker? Many of the patterns on that old map still match present-day maps of poverty, public investment, and even tree canopy coverage.

WHY IT CHANGED ME

Because it made something painfully clear: cities don’t just happen. They’re planned and sometimes, they’re planned to exclude. It showed me that if we’re not actively working to dismantle unjust systems, we’re leaving them in place.

Maps can open eyes, and as planners, we have a responsibility to use them not just to see, but to change what we see.

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