highway/ expressway/ thruway /freeway有什么区别？

A highway denotes any paved road that provides transportation for vehicles. May be 2 lane or four lane, divided or not. Back in the 40s-50s, some states, Virgina when I lived there, built 3 lane highways, the middle for passing only. They became deadly when some drivers, in both directions, drove the middle lane and at blind spots caused head on collisions. They were finally outlawed and changed to 4 lanes.

An expressway is normally a 4 lane divided highway that may have limited access, entrances and exits, which may include overpasses, over intersections. It may be toll or not.

Freeways described the first 4 lane highways just like our Interstate system. They were not always free. Some charged a usage fee from the entrance to the exit by drivers. They did not have frequent toll booths, only at entrances, where a ticket was issued, and exits. One of the first, prior to Interstates was the Pennsylvania Turnpike, as it was called back then. They were built to eli