Research On Planning And Layout Of Zhengzhou Urban Expressway Network Based On Analytic Hierarchy Process

With the rapid urbanization of large and medium-sized cities in China recently,the urban size has been expanding ceaselessly as well as the population and vehicles.The excessive population and vehicles that swarm into the city bring out the land overdevelopment,disordered urban zones,traffic congestion and other chaotic phenomena.At the same time,due to the appearance of new city groups around the city such as new urban district,university town,industrial estate,etc.,the traffic demand of urban residents on long-distance commuting is also increasing.Therefore,in order to prevent the unrestricted expansion,the state guides the city to transform to stock planning direction in recent years.Although urban development takes the elaboration and habitability as strategies,the urban border is also relatively stable and large demolish and construction in internal part of built-up area is prohibited,many matched infrastructures in inner city are imperfect in contrast to the relatively mature urban construction.For instance,the urban transportation system,especially the urban expressway network whose overall arrangement fails to form a complete system,cannot alleviate urban congestion effectively but result in more traffic demands and new traffic bottlenecks.As a part of the urban road traffic system,the urban expressway network is the backbone urban road network and the core of the urban road network structure.For its highly motorized characteristics,it can meet the traffic needs among the urban areas,the urban core areas and the outer groups.Though the developed cities in Europe and the United States don't advocate the construction of new urban expressway,it's been a long time since the developed western countries started urban construction.Their urban traffic system is relatively mature and its urban expressway network has formed a complete system which can undertake most motor vehicle traffic flow in city,and supplement with the urban slow-moving traffic and public transport.However,urban expressway network of large and medium-sized cities in China is still at initial stage and needs more reasonable guidance and analysis to obtain the optimal layout schemes.In view of the above problems,this paper put forward the idea of applying AHP method to study the planning and layout of Zhengzhou urban expressway network.First of all,the paper expounded the origin and theoretical basis of the development of urban expressway,and studied the expressway construction experience at home and abroad to summarize the characteristics of urban expressway.On the basis of that,the paper explored a calculation method for reasonable urban expressway scale,including the supply and demand balance method,regression analysis method and so on,and the applicability analysis was carried out too.As a basic element in expressway network planning and layout,reasonable scale is a rather essential prerequisite.And then the common theoretical methods of urban expressway network planning and layout in China were summarized.Due to the one-sidedness of these methods,a relatively comprehensive analytic hierarchy process was introduced in this paper to study the planning and layout of urban expressway network.The elements that influenced the layout of urban expressway network were divided by point-linesurface analytic hierarchy process that derived from the analytic hierarchy process into point,line and surface levels and were analyzed from the perspectives of microcosmic,middle and macroscopic.Finally,a comprehensive planning and layout scheme was concluded.After the research on point-line-surface analytic hierarchy process,it was introduced into the planning and layout of Zhengzhou expressway network.The fourth chapter of paper analyzed and researched the historical process,current situation and development trend of Zhengzhou urban development and urban traffic,including the characteristics of economy,population,urban development strategies,travel of residents and so on.Finally,the interaction relationship between Zhengzhou urban traffic and urban spatial structure at each stage were summarized.On the basis of the above,the Zhengzhou urban expressway network planning and layout scheme was obtained by point-line-surface analytic hierarchy process in Fifth chapter.Besides,the Zhengzhou expressway at the present stage was compared and evaluated.On the one hand,the study on point-line-surface analytic hierarchy process and the layout of Zhengzhou urban expressway network contributes to rationalizing and completing the Zhengzhou expressway network system,meets the growing traffic demands for long-distance commuting,evacuates the traffic in the core area of urban and alleviates traffic congestion.On the other hand,the construction of urban expressway network together with the slow-moving traffic and public transport can form a complete urban road transport system that enables the smooth link of the expressway,urban traffic and other classified highway.It plays an important linkage role,and ultimately realizing coordinated development of traffic,residents and the city.