Here's what I was thinking of
El curve over road curve
El T over Road T
El + over road +
El curve over road +
El curve over road T
I am ready and willing to model (and possibly texture) peices for these ;D, someone else would need to modd them
Start working on them and show some progress or results. If it looks good then I am sure some transit guru's will step in and help you get them into the game.