China's Rapid Urban Road Layout Method Study

On the base of analyzing the characteristic. function .layout basic theory of city expressway and the present expressway practice , this article constructs the basic theory system which primary study content is layout and design of expressway lines and net as well as the design of expressway network nodes. And puts forward the method and steps by which make sure the line-position, using the city transportation location theory. By analyzing and comparing the network feature index-non-beeline coefficient. shortcut index .joint degree index ,demonstrates the cobweb theory that in the conditions which has the same area. scale and density, round-radiation network has the best traffic efficiency. Making use of the cobweb theory, designs the expressway network and makes sure the round intervals and radiation density. At last by the study result that the round intervals and radiation density of round-radiation network, instructs the lines and network layout, adjusts and optimizes the round and radiation lines distribution and amount which come from the location theory, then obtains the final spacial form of expressway network. By analyzing the node crossroads form choice and demonstrating the incidence of expressway passageway, puts forward the theory interval with which expressway passageway is satisfied. Aim at the layout scheme of city expressway, the paper puts forward the step and method of adopt vague comprehensive appraisement, final, combine the expressway system's layout plan of Xi'an, to verify the correct reasonability of the paper's layout method.