How would you make tracks like in Line Color 3D?

I’m trying to make a game that would use a track similar to the ones in Line Color 3D:

So this looks basically like it’s a mesh extruded along a bezier path. But I’m not sure how to handle the road intersections.

Ideally I would like to be able to provide a path and generate the mesh, but dealing with all the intersections in code seems way too complex.

On the other hand, I could maybe make the tracks in Blender and manually edit the mesh, remove faces, weld vertices, to get what I want. But that means any changes I want to make to the track will be a pain.

I’m looking for suggestions on how to approach this.

My solution was to add a drop shadow effect.

So i duplicated the bezier path, placed it on the bottom of the original path, changed the duplicated path to a much darker color and changed the offset of the shadow path’s X and Z position depending on the cameras X and Z position.