Mike, Rob figured out what your fastracks close to the edge would leave!
031 Tubular rail would be at least bankable.
You could always set up a fence or a baracade around the fast tracks or have a restricted speed limit. Best of luck.
Check your clearances as you build. Steam cow catchers and cabs, and diesel pilots hang over a lot on a 031 curve. Even worse on 027 (ask me how I know )
Leroof's video is a good example.
Here's how it looks in SCARM. Board is 36" wide.