I figured out a couple more ideas. The above idea is possibly impossible to do with a track. If it's randomly generated it might not create an enviroment that can be used to put a track on.
As kimden said
kimden {l Wrote}:I do not understand very clearly what that means, but assuming you want to build a track that is generated randomly and also may change randomly between starts, it may be a difficult task and probably not really worth it
• tracks usually use curves to have smooth turns, and completely random things usually involve piecewise straight parts which are kind of bad for the tracks, or fractals like mandelbrot's but they are too curvy...
• to make it changing between runs, scripting is needed even if there are a few routes only (check out random roads), with many 3d objects to hide and show it's going to be difficult
Checkpoints -- One idea to overcome problems with unevenness in the environment with roads is to just have checkpoints without roads.
Linear or downhill levels -- Some snowboard games have linear levels with a ski lift to bring them to the top to run the lap again. We could just have the bird carry us to the beginning.
elevation map -- also had the idea of a 3d elevation map.
A River/Sand -- it's said: "you can never step in the same river twice." When you do it changes.
Someone had procedural track generator but its under MIT Licensing.
For tracks that are licensed differently you could have addon packs so they wouldn't be a part of and couldn't be included with STK.