【摘要】 高速公路的飞速发展,对国民经济的发展产生了巨大的推进作用,同时国民经济的发展也对高速公路的各项服务提出了越来越多的要求。随着高速公路覆盖率的快速增加,便捷性越来越高,总体服务质量也较普通公路优越,因而越来越多的出行首选高速公路。原有一级或二级公路的通行能力将面临前所未有的挑战,改扩建工程就显得十分必要和紧迫。更多还原

【Abstract】 The fast development of expressways greatly promotes the development of national economy and at the same time the development of national economy put more requirements on the services of expressways.With more and more expressways built,more and more people choose expressways for traveling for the convenience and better service than ordinary roads.The passage of first-class and secondclass roads is facing unprecedented challenge,so reconstruction is necessary and urgent.更多还原