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

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 eliminate as many blind curves as possible and many were cut through hills and mountains,saving mileage and travel time for drivers,as well as a safety measure.
Throughway's are usually 4 lane,divided or not,usually free,may be toll,to route traffic away from city intersections.
This is not common usage.Most of these kinds are Tollways,4 lanes,divided,and routes traffic away from congested areas.
Our Interstate System was initiated by President Eisenhower.These are our present multi lane highways that originally connected major cities around the country.They have constantly been expanded and some are completely through from North to South,East to West.
Interstate Loops are circular Interstate highways that route traffic around the city and interconnect with cross country interstates.
Houston,TX,now has 3 loops around the city.
The inner loop about 10 miles from downtown,interconnecting an outer loop about 15-20 miles out,and a loop out about 40-50 miles from downtown.All these avoid inner city traffic.All connect to cross country routes.
The newest Interstates planned are called "Corridors,stretching from Mexico to Canada,by the shortest possible routes.
Sorry this is so long but it's a long subject.