Sustainable Development of Urban Traffic and Underground Expressway

From the perspective of the sustainable development of urban traffic and the construction of abstemious city,the necessity and feasibility of building and developing underground expressway which is specially used by automobile was analyzed,The results show that building underground expressway can not only lessen traffic jam,but also accord with the demand of saving land,which doesn't have fatal difficulties in economy,technology and environment.For those big cities with serious traffic jams and short of land that can be used in traffic,building underground expressway is one of the optional ways for realizing the sustainable development of the urban traffic.