The Church of Alvis

Placing half-height slabs above the tracks works. It is too short for pigmen to get under, but doesn't suffocate you while in a cart. Also, because your head is 'inside' of the blocks, you don't see them while riding on the cart. I added a section of 200 on the rail to Maizan's as a test. It seems to be working.

My shader and resource pack does some crazy stuff with this. I can see the blocks as a two dimensional plane at certain viewing angles (for my toon).

But it DOES work great!