There is a world where we dig tunnels under federal highways, and stick freight trucks down there. They'd run on a monorail, at 120+ mph. Surface vehicles would be dramatically limited in terms of height, width, and length. Maybe people buses could go down there? In my imagination these tunnels are, like, 200' down. Like mole people.
I just invented trains again didnt I? Whatever you do, you always end up with trains