Great writeup. Along similar lines, the East fork of the San Gabriel river is a bit outside Los Angeles. It has a dead-end road with two tunnels to nowhere, abandoned in the 1960s. Below that is a massive bridge to nowhere that connected to an under-construction road that was abandoned in the 1930s, with all traces of the road largely gone; except the bridge, which is huge and is very much still there. Much more obscure is the PL&P trail, a bit above the bridge. Built and abandoned in the 1910s. All in the same canyon!

Less deep history, but a similar looking tunnel in Pennsylvania - https://en.wikipedia.org/wiki/Abandoned_Pennsylvania_Turnpik... . The most interesting thing about it is probably that it was used to film The Road.

They make for nice conversions to bike paths and hiking trails at least?

For those of us in Southern California there’s a similar attraction in the San Gabriel Mountains called the Bridge to Nowhere [1] along the East Fork. It was originally built in 1936 (for the gold miners IIRC) and then a massive flood in 1938 wiped out all the roads leading to it along with the miner camp. Afterwards engineers figured it wasn’t worth building anything there because the floods would continue to destroy them.

[1] https://en.wikipedia.org/wiki/Bridge_to_Nowhere_(San_Gabriel...

Had the road been completed, Bryson City could have also become another Gatlinburg (as the road would be an entrance to the National Park), with the tourist revenue that goes with that. When I lived in NC 25 years ago, locals were obviously miffed about that, too. Access to cemeteries never seemed to come up.