交通运输是国民经济的基础产业,也是促进社会发展和提高人民生活水平的基本条件。天津作为我国的一个直辖市,完善的综合交通运输体系是确保其成为环渤海地区经济中心、现代化港口城市和我国北方经济中心地位的重要条件。公路交通建设发展是综合交通运输的基础,这种基础性作用体现在微血管和大动脉的双重功能上。所谓大动脉,是指公路将在大的通道交通中发挥重要作用。随着我国经济结构的调整和运输需求结构的变化,公路承担的运输任务将继续快速增长,公路运输的大动脉作用将越来越显著。所谓微血管, Transportation is a basic industry of the national economy and a basic condition for promoting social development and improving people’s living standard. As a municipality directly under the Central Government in China, a sound integrated transportation system is an important condition for ensuring that Tianjin becomes a center of economic development in the Bohai Rim, a modern port city and a northern economic center in our country. The development of road traffic construction is the basis of integrated transport. This fundamental role is reflected in the dual functions of capillaries and aorta. The so-called aorta means that roads will play an important role in the passage of large lanes. With the adjustment of China’s economic structure and changes in the structure of transportation demand, the transportation tasks undertaken by the highway will continue to grow rapidly and the aorta of road transportation will become more and more significant. The so-called microvascular,