Rail generator
With these OpenSCAD scripts You can generate railway tracks - use "rail_stright.scad" or "rail_curve.scad". Rail profile is in "profile.scad" - if You are familiar with OpenSCAD You can replace it with Your own.
This is really just rails generator - sleepers and mounts are STL models. I've included ones for 1:87 scale. You can scale them, but probably for other scale You will need other models.
You can use these sleepers:
https://www.thingiverse.com/thing:5453842
https://www.thingiverse.com/thing:5596566
Some samples included.