It's alpha as still learning track builder and it is not quite perfect yet, but should be usable.
"Horseshoe" is bit off, kinks to left bit too tightly, imo, even I made it to follow real layout and inclines are not verified in any way, just from memory (I have done few laps on this track IRL), so those are areas to improve I think. Also banking, it might be bit much at some places.
It is kinda fun to drive though, some parts you might need to practice a bit to get them right.
How to use:
Time trials -> track builder tracks > Racetrack one
Discussion (wishes, bugs etc) :https://www.beamng.com/threads/racetrack-one.59048/
Thanks to TStabbert from tips how to improve the track.