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 (州際的) highway
-Highway patrol officers (州際公路巡警) closed the road.
Meaning 2: 【英】公用道路；公路。
(British English, formal) a public road
【美】高速公路 (highway的其中一類: 部分控制進入的快速道路 ) 指的是車速限制較低，不全部採用立體交叉，部分控制進入的城市快車道。
(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.
【美】高速公路 (highway的其中一類: 控制進入的高速公路 )
(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: 免費高速公路 a toll-free highway
(in Britain) a wide road, with at least two lanes in each direction, where traffic can travel fast for long distances between large towns.
A. Tollway 等於 toll road，指 a road for the use of which a toll in collected（收費公路）。
-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 指柵門，turnpike road 指收費公路，簡稱turnpike。
-a wide road, where traffic can travel fast for long distances and that drivers must pay a toll to use
C. Parkway 則有數義：1. 刻意綠化之交通幹道，尤其指卡車及其他重型車輛不准通行者；2. 公園中之道路；3. 通過公園之高速公路，故不對重型車輛開放。
-a wide road with trees and grass along the sides or middle
D. Superhighway is a broad arterial highway designed for high-speed traffic。
Image source: http://tinyurl.com/q5gzb97