I know this isn’t GQ, but I think a Pipeline coaster sounds very similar to the OP with the exception of only two rails - one on each side.
The pic on that page shows an inline barrel roll. Apparently the coaster type didn’t work out. (I only remember this from Rollercoaster Tycoon.)
I like the happy peepz in the diagram.
Sweet. I’m impressed that someone actually attempted the two-rail version. I still think three would allow it to execute tighter maneuvers, but who knows.
They’s mah peepz, yo.
Then what you’re after is this
That is interesting. The demo video seemed like the opening shots of a Sim City game, though. Kind of odd. I mean, if uncanny valley could be used to describe landscape animation, this video would be the example. It’s so almost-real, but clearly not real that for some reason it creeps me out a little…