I love the idea of this, and I so far, it looks beautiful. I'll list some ideas for tracks (assuming you're going based off official maps):
Viaduct (Snow themed, probably a wide track)
Hydro (Maybe you go over the dam w/ a pit?)
Egypt (Uses lots of right angles)
Upward (A cliff loops around the track, but easy to take turns)
Swiftwater (A longer, but very green track)
Landfall (Big tree based turn)
Freight (Train based shortcut maybe?)
Degroot (Medieval based track)
Gorge (Some nice rivers cutting through the track)
Granary (Uses big crates/pipes from last)
I know this is a big comment, but I want to help you out if you need any. Once again, love this idea, and I hope it catches on quickly. 'u'
