...were one of the things I found interesting in the movie. It must be the only time(?) we see street level action on Earth in this time period. I'm ready to be proved wrong in many ways there.
Anyways, there seemed to be metal strips running along the road from what I remember. I took it as a way that cars can drive themselves using these special roads if the driver wasn't interested in doing it themselves.
Maybe there's more detail out there I could look up?