我国的高速公路建设是从20世纪60年代末开始的,截止到2001年底,我国已建成19000公里高速公路,总里程数居世界第二位。高速公路的主要特点是:交通流量大、行车速度快、渠化程度高、桥涵等构造物多、公路设施比较齐全,全路段封闭或部分封闭。它们一般构成国家公路网主骨架,是国家 China’s expressway construction started from the late 1960s. By the end of 2001, China had built 19,000km of expressways, ranking second in the world in total mileage. The main features of the expressway are: large traffic flow, fast driving speed, high degree of canalization, many structures such as bridges and culverts, relatively complete road facilities, enclosed or partially enclosed roads. They generally constitute the main backbone of the national highway network is the country