Verifying the southern leg of the Cincinnati Subway

Continuing the discussion from Proposing to deprecate railway=razed and railway=dismantled:

In this changeset, @nickvet419 mapped the abandoned subway tunnel as if it turns south from Central Parkway to follow Walnut Street down to Fountain Square, where it makes a tight loop around the block. After I challenged this assertion several years later, he specifically elaborated that the two bores are “blocked off” around 5th and 6th streets, without citing any source, but deleted the loop and the Walnut Street alignment, claiming they are “walled off and not accessible to be mapped”.

I thank Nick for making these corrections. For what it’s worth, I can find no evidence that the deleted segments exist at all. Every source I’ve found so far makes clear that construction never made it south of Central Parkway, for example:

On the other hand, I did come across a map that depicts the same route as a dotted red line, but this is apparently based on the 1927 Beeler Report, not what got built.

It’s entirely possible that these sources are misleading and that someone who actually takes one of the tours would learn more about what’s down there. Several years ago, I went on a much shorter underground tour in the nearby Over-the-Rhine neighborhood and found some things to map that weren’t on existing maps, including this beer smuggling tunnel under the headquarters of Roadtrippers (incidentally an OSM data consumer). However, I think the sources now vaguely cited in a description are less reliable than the more obvious sources.

For sure, a good chunk of the subway tunnel should remain in OSM. Central Parkway is essentially its roof, and a layperson can peer into some portions of it through ventilation shafts. Apparently there are even preserved railroad ties in some places.

Edit: I didn’t notice when writing this post that the most problematic portions of the route had already been deleted, due to an Overpass query that specified a date:. My apologies for overreacting. Still, hopefully we can finally put a conclusion to this whole situation and clean up the misunderstandings that have spread beyond OSM.