Research On Integrated Layout Planning Of Highway And Expressway In Metropolitan Area

Integrated urban functional areas generate with metropolis expanding, and industrial relations and transport links have become more and more intimate between the central urban area and the outside new districts. Highway and expressway mainly meet the urban rapid travel of long-distances. Integrated layout planning is conducive to forming the city reasonable passenger and freight fast track, and easing the pressure on urban traffic, and building convenient and efficient external traffic cohesion conversion system.This paper analyzed the evolution of urban spatial structure, and the interaction between highway-expressway system and urban spatial structure, population and industry distribution, road network. Metropolitan hub-and-spoke organization model of external traffic is proposed. The transportation facilities characteristics of highway and expressway, and differences and similarities compatibility on the functional structure, facilities standard, traffic flow are analyzed. The meaning of the integration layout planning is explained.The demands of urban through traffic, entry-exit traffic and internal traffic are predicted, combined with demand characteristics of highway and expressway. The road network capacity is analyzed, combined with facilities supplying characteristics of highway and expressway. From the network function and transportation ridership, the network reasonable scale is calculated by using the method of supply and demand balance. The regression analysis model about the scale of highway and expressway is established, by application of the scale, society, economy, transport and other data of mature cities.The layout shape of urban space and highway and expressway are analyzed, and the control elements are sorted out from three levels of "area, line, point". Superposition and separation layout planning thinking is put forward, meaning hierarchical layout, superposition of cohesion, global optimization. The method of generating initial network about highway and expressway is focused. The urban Freeway Corridor determination technology is put forward, relying on spider web traffic assignment. The range of loop radius is researched through theoretical calculations and city case. The virtual network is generated based on importance of nodes and path random search method. The network layout scheme is obtained after matching the actual road network.The social, economic, environmental, urban form, and other aspects about the cohesion node location layout of highway and expressway are analyzed, and setting principles are given. The location decision thinking is researched. The objective optimization model about cohesion node initial position selector is established. The index System about cohesion node location decisions is constructed by using analytic hierarchy process, and multistage fuzzy comprehensive decision and assessment model is established.Taking Nanjing metropolitan area as an example, predict traffic demand and scale of highway and expressway in the programming year. The integrated layout planning method is applied to the practice, and the integrated layout scheme is obtained.