Very cool idea! I really enjoyed the constant reconfiguration.
I have two suggestions for you to consider.
1: Having the color coding on the ruggedness be a bit more intuitive would be good.
2: A 'Clear Tracks' button. Once your track piece count gets high enough the clicking gets pretty tedious. If you had an option to clear your existing pieces from the play surface into a toolbar or something, i think it would cut down on that.
Again very cool idea and well executed. Thanks!