Yes, historical zoning would be very interesting to map. For one thing, I get asked a lot about whether OHM would be a good place to recreate HOLC redlining maps, which isn’t quite the same thing but comes up in any discussion of historical zoning. I want to be able to say yes to that question, because most existing visualizations only show the old maps themselves or the neighborhood classifications overlaid upon a modern-day map, and we can do better than that.
Mapping this sort of thing will come with a tradeoff in complexity, since our data model lumps everything into one big layer, unlike in traditional GIS. Ideally, in any region where you map zoning, you’d be taking some responsibility for our coverage of these neighborhoods overall, to make sure our coverage remains coherent.
As you note, zoning can influence landuse. Most landuse areas in OHM are based on old general-interest maps, which are only a snapshot in time. Zoning boundary data would give us a better foundation for mapping changes to landuse patterns, even with the caveat that zoning doesn’t guarantee immediate construction. We also have a couple of mappers going off of plat maps, which might interact with zoning data too.
I encountered this problem when mapping ranchos in California. The Spanish and Mexican governors would grant permission to use an area for a specific purpose but reserved the right to grant the same area to someone else for some other purpose. This generated lots of lawsuits in the early American period, when the state transitioned from land tenure to land ownership. So far, I’ve only mapped the ranchos according to the claimant who ultimately won out in court – so their granted use of the land – but there’s probably more nuance waiting to be dug up.
I wonder if we might need to treat modern U.S. zoning as a different concept than in other countries, similar to how we’ve got time zone boundaries as a first-class concept in the U.S., but not in other countries that conceive of a time zone as merely an attribute of a country or province.