use a wall, flating the center nodes.and move to position
I tried that, but it seems, that there are problems with rendering, because sometimes the "painted lines" are disappearing into the ground. Not always, just at some Parts.
That will be where they are too close to the ground at that point. AFAIK the line should be 2 cm+ above the track surface. Try adding extra control points where it's too low and raising it up a bit.