Hi, I see that you attempted to keep OSM data consumers from misinterpreting the planned subway stations as active subway stations, but you need to use abandoned:railway=station or something like that. Otherwise, every data consumer currently thinks these are active subway stations, because they understand railway=station but not abandoned:railway=yes.

More generally, I think you’ll find that OSM is not a great home for information like this. We have a sister project, OpenHistoricalMap, that focuses more broadly on the past and present. It covers the Miami & Erie Canal [1] and Central Parkway but currently lacks the subway infrastructure, which would be more than welcome there. I dug up some references you could use for determining which parts of the proposed southern leg were built. [2]

In the meantime, would you mind at least retagging these stations or preferably deleting them, so they don’t mislead people looking for public transit directions? Thanks for understanding.

[1] https://www.openhistoricalmap.org/#map=17/39.107994/-84.515934&layers=O&date=1920-01-01&daterange=1788-01-01,2025-12-31
[2] https://community.openstreetmap.org/t/verifying-the-southern-leg-of-the-cincinnati-subway/115820