1. highway
Meaning 1: 【美】大道；要道。
(especially North American English) a main road for traveling long distances, especially one connecting and going through cities and towns.
-an interstate (州际的) highway
-Highway patrol officers (州际公路巡警) closed the road.
Meaning 2: 【英】公用道路；公路。
(British English, formal) a public road
2. expressway
【美】高速公路 (highway的其中一类: 部分控制进入的快速道路 ) 指的是车速限制较低，不全部采用立体交叉，部分控制进入的城市快车道。
(in the US) a wide road that allows traffic to travel fast through a city or other area where many people live. Expressway is the equivalent of what used to be called “Limited Access Roads.” These roads may have some interchanges or stop signs where local roads connect to it.
3. freeway
【美】高速公路 (highway的其中一类: 控制进入的高速公路 )
(in the US) a wide road, where traffic can travel fast for long distances. You can only enter and leave freeways at special ramps (高速公路特殊坡道). Freeway is the equivalent of what used to be called “Controlled Access Roads.” These are roads that can only be accessed by ramps (no traffic lights), and are free from slow-moving traffic.
Meaning 2: 免费高速公路 a toll-free highway
4. motorway
【英】高速公路 (=【美】expressway)
(in Britain) a wide road, with at least two lanes in each direction, where traffic can travel fast for long distances between large towns.
5. Misc:
A. Tollway 等于 toll road，指 a road for the use of which a toll in collected（收费公路）。
-a road that drivers must pay to use. In the US such roads are now mostly motorways/highways. The money may be collected from drivers as they join or leave them.
B. Turnpike 指栅门，turnpike road 指收费公路，简称turnpike。
-a wide road, where traffic can travel fast for long distances and that drivers must pay a toll to use
C. Parkway 则有数义：1. 刻意绿化之交通干道，尤其指卡车及其他重型车辆不准通行者；2. 公园中之道路；3. 通过公园之高速公路，故不对重型车辆开放。
-a wide road with trees and grass along the sides or middle
D. Superhighway is a broad arterial highway designed for high-speed traffic。
