Spatial Evolution And Spatial Effect Of Road Network Efficiency In Shanghai

The intricate road network is like vessel,in-depth portrait of the urban fabric,and presents a complex self-organization.The spatial efficiency of road network has become the “prism” that reflects self-organization mechanism of urban roads’ supply and demand system,which not only provides a new perspective for the complexity of urban transportation geography,but also provides guiding practice to the contradiction between the limited supply of transport and the diversified needs of residents in large cities.In order to solve the ineffective problem and traffic congestion in mega-cities,taking Shanghai as an example,in three dimensions of spatial variation,spatial agglomeration and spatial effects,this paper portrays the evolution process of spatial heterogeneity and spatial effects of Shanghai’s road network efficiency by building a multi-scale road network efficiency model,utilize spatial statistics(Gini coefficient,Theil coefficient,spatial regression),and spatial analysis(nuclear Methods such as density estimation and exploratory spatial analysis)and acquire seveal findings :Regardless of local efficiency or global efficiency,it is significant that the characteristics of spatial heterogeneity of road network efficiency in Shanghai presents "core-edge" spatial differentiation pattern and the spatial agglomeration of "large agglomeration and small dispersion" law.In addation,flakes and clusters are the main modes of high agglomeration.In the past ten years,changes have been consistent with the urban land expansion patterns in Shanghai,and it presents typical spatial "stickiness" or inertia.That is,the "core" and "periphery" areas of road network efficiency values remain relatively stable.The high-high agglomeration areas are locked in the central urban area within the inner ring line,while the point-shaped high agglomeration areas are embedded in the central towns of Qingpu,Songjiang,Jinshan,Minhang and Jiading.What is slightly different is that there are significant differences between the agglomeration and diffusion patterns of the local-global efficiency of Shanghai road network.Among them,the local efficiency only depends on the connectivity and node distance of the local road network,while the global efficiency fully considers the geometric location of the road crossing node in theglobal scope,and the urban trunk roads such as circular and radial roads.Shanghai’s road network efficiency has a close association with the development of social economy.The global efficiency effect on population,house prices,innovation and services is more obviously than that of local area efficiency.Over time,the correlation between Shanghai’s social economy and road network efficiency shows an increasing trend.However,individual appears "abnormalities",such as urban innovation and education service outlets.