Folks have been doing it for a long time, just not with equipment that nice.
First time I saw a rig riding the rails, very similar to what Herr_oberst described, was in Anza-Borrego outside of San Diego. I loved hiking there in what passes for winter in that area.
https://www.onlyinyourstate.com/southern-california/trestle-bridge-usa/
This was in the mid 80's.
I have not personally done it.