I think that usage is mostly West Coast. :)
Everywhere else, I've only heard "highway" or "interstate."
http://www4.uwm.edu/FLL/linguistics/dialect/staticmaps/q_79....
In common usage highway is still sort of reserved for larger connectors, road and street are used for local stuff.
I think that usage is mostly West Coast. :)
Everywhere else, I've only heard "highway" or "interstate."