In those shots the rail is 3D. But I had to change them to 2D due to a massive moire effect caused by the 3D rails at a distance.
See @LilSKi post back on page 1, his NJMP turn 5 is essentially what you are trying to do, and I think I’ll do the same, I’m just going to delete my extra dirt edge mesh and work with the grass mesh and better resolution diffuse with proper masking. I’ll post progress shots so we can learn together!