交通运输是国民经济和社会发展的重要基础,随着公路运输的快速发展,交通需求日益增加,交通拥堵、交通事故频发和交通环境恶化等已成为当前世界各国面临的共同问题。解决交通问题的传统办法是修建或扩建道路,但是,随着人 With the rapid development of road transport, traffic demand is increasing day by day. Traffic congestion, frequent traffic accidents and deteriorating traffic environment have become the common problems that all countries in the world nowadays face. Transportation is the important foundation of national economy and social development. The traditional solution to traffic problems is to build or expand roads, however, along with people