A lot of zoning restrictions were an attempt to circumvent anti-segretation laws for schools and housing through policies such as redlining.
You can't understand American city structure without the context of race relations here.
Hoping to evoke a Keystone Cops-on-a-map style mental image.
Didn't mean the phrasing literally, as much as in parody. That said, there is an element of upwardly mobile African Americans seeking opportunities for their children. While they are not explicitly "chasing white people", this search frequently lands them in the same suburban locales.
- https://en.wikipedia.org/wiki/Zoning#Functional_zoning_-_cat...
- https://en.wikipedia.org/wiki/Zoning#Criticism_of_zoning_law...
Then that Wikipedia article needs to be amended.
Look at an example from the real world. This is happening right now, in Portland Oregon. http://www.portlandmercury.com/portland/two-portland-glass-c...
The problem is that glass factories are "adjacent to a 100-child daycare facility, two public schools (Cleveland High School and Winterhaven K-8), and a city park."
These factories have been emitting metals such as cadmium and arsenic into the air. As you can imagine, this being Portland, everyone is quite upset. And rightly so.
You can argue about the quantities of emission that any given plant should be allowed. But you can't argue that, for any given emission level, society as a whole is much better off if these factories aren't adjacent to daycare facilities and schools.
Keeping schools and factories separated is a very legitimate "safety" goal of zoning.