Also...
Export to STL is a great command, but..
The ground comes in as a surface only and can't be 3D printed like the track/roadbed which has a thickness.

Please consider this, it could make ANYrail the GOTO software to design then 3Dprint a layout - in smaller sections of course

thank you.

Which code rail are you looking at? Code 55 already has a 17.5" radius.

Code 80
Atlas N 2525 Code 80 17" Radius Curve Track