- Puts three time layers on one tract map so people can compare them directly.
- Helps show where older exposure and present-day strain still appear to overlap.
- Gives each tract a readable pattern name in Composite Read mode.
RTE Local Viewer
How to Read the Ghost Layers
This page is for people who are new to the map. It explains what you are looking at, what the colors mean, and where the viewer is careful. The map is not an official city publication. It works best as a visual aid for seeing how older decisions still seem to show up in present-day Memphis.
What This Is
A visual aid, not an official city map
This viewer is not trying to prove that every tract is frozen in exactly the same condition it was in during the 1930s. It is asking a narrower question: if you lay the old HOLC footprint, a present-day continuation estimate, and today's burden score on the same tract grid, where do they still reinforce each other?
That matters because a place can look contemporary on its face while still carrying the shape of older decisions underneath it. The map is built to make that overlap visible instead of leaving it buried in separate layers no one sees at the same time.
- Claim that HOLC alone explains Memphis.
- Prove that every neighborhood or boundary is unchanged since the 1930s.
- Replace field knowledge, local history, or block-level reporting.
Fast Read
Read it in 20 seconds
Start with the Composite Read. That is the fastest way to see whether the old map, the continuation estimate, and today's burden score are reinforcing one another or breaking apart.
- Warm colors: older exposure and present-day strain are still lining up, either on the same ground or after the burden moved.
- Cool colors: protection held more strongly, or the tract now reads more protected than the historical map would suggest.
- Click a tract: compare the HOLC touch, the continuation estimate, and the ZIP / Place label for orientation.
1930s HOLC
The original redlining-era footprint. It stays inside the ground the historical map actually covered.
Continuation Estimate
A present-day estimate of where the old sorting logic still seems most likely to land.
Today's Burden
The current strain layer showing where burden is actually landing now.
What the composite colors are saying
When the map lights up in red or orange, it is usually showing burden that either stayed where historical exposure already was or migrated into new ground while still following the old grain of the city. Blue and green usually show places where protection held more strongly or was rewritten more favorably.
Plain-English Method
How the viewer is built
- HOLC stands for Home Owners' Loan Corporation, the New Deal-era agency whose residential security maps helped formalize redlining.
- The historical layer stays as a partial footprint rather than being stretched across places the original map never covered.
- The continuation estimate is built from present-day public signals tied to lending gap, wealth strain, institutional change, and a light grocery-continuity lane.
- Where the needed tract inputs are incomplete, the estimate is withheld instead of guessed.
- The burden score starts as a published ZIP-area layer and is joined down to tracts by weighted overlap.
- Food retail presence is not the same as full-basket grocery ease. A household may still have to stitch together groceries across multiple stores, trips, and transit or gas costs.
- That makes the viewer good at citywide pattern reading, but not a substitute for block-level field verification.
Words you will see
Census tractA small census geography used here as the shared map unit.
ZCTAThe Census Bureau's ZIP Code area approximation.
Burden scoreThe viewer's measure of where present-day strain is landing.
ZIP / PlaceAn orientation label in the tract inspector, not a strict municipal boundary line.
Where to be careful
This viewer is strongest as a structural pattern reader. It is not claiming a one-to-one legal continuation of HOLC, and it is not pretending that a ZIP-area burden score weighted into tracts is as precise as a tract-native burden model would be.
Those caveats do not erase the pattern. They mainly define how careful to be when moving from citywide interpretation to a tract-by-tract argument.
Why It Matters
It gives people something to see first
If the same parts of the city keep lighting up after you stack the old map, the continuation estimate, and the present burden score, that suggests today's hardship is not only about today's choices. It suggests the city is still carrying older decisions inside the present.
That includes burdens that do not always show up cleanly in a simple inventory count. A ZIP can have food retail on paper and still force families into a hidden grocery tax in extra stops, extra time, extra gas, extra bus rides, and fragmented shopping just to keep the fridge full.
That is why the viewer matters. It turns a hard-to-explain structural argument into something spatial and inspectable: you can click a tract and see how the historical footprint, the estimate, and the current burden either line up or break apart.
Use it for
Showing continuity, orienting people to the tract story, and helping others see why present burden often does not appear out of nowhere.
Keep in mind
Back to viewer
This is an interpretive tool built from public data and local observation. It is strongest as a visual argument you can inspect, not as an official ruling on any single tract.