Interactive Evolution Mechanism And Coordinate Optimization Of Urban Transportation Infrastructure And Economic Scale Distribution

City scale is a social and economic concept reflecting the aggregation and diffusion degree of material and elements in the city geographical space. Speaking from the perspective of social development, city scale is the "flow" inside the cities, this "flow" is the dynamic features that happened during evolution of urban demand and supply, including people, physical and economic mobility. Speaking from the perspective of urban planning, city scale is the "block" inside the cities, the "block" is the distribution form in different location due to the difference and hierarchy that urban elements gathered. "Flow" is the dynamic performance of city scale and exchanges and evolutions of human, economic, and space scale during the scales formation, "block" is the static performance of city scale and the aggregate form that accumulated during constant evolutions, city scale distribution form is coordinate between dynamic and static. As an "economic landscape," city is not only the highest expression of economic spatial pattern, but also the result of socio-economic activities in space gathering. Many researches proved the positive correlation between economy, population and space, economic scale always affects the development of the overall city scales, just like an invisible hand, that means economy is a major factor of the urban scale development.With the continuous expansion of city scale, blindly increase or limit the transportation construction will make transportation become a short-board of city system, it is difficult to explain the most fundamental issues of transportation infrastructure construction purely pay attention to the perspective of supplies. Some articles separate analyzed the city distribution pattern or transportation networks form, lacking of the interaction evolution mechanism and coordination coupling process between two aspects during city development, constructed evolutionary model from system "iteration", ignored the "interactive" process. Therefore, this paper build a comprehensive transportation system based on economic distribution and transportation infrastructure, put an eye on interactive coordination and coupling optimization between transport infrastructure networks and economy scale distribution.try to reveal the internal mechanism and the laws in the development process combining qualitative and quantitative research, aim to analyze, identify and solve the interaction and coordination problem between traffic and economy under different city development stages,giving theoretical reference to the city effective decision-making on transport infrastructure investment.The essence of crossfeed influence and mutual adjustment process between transportation infrastructure and economic distribution is the process of system optimization. However, due to the stealth characteristics of the system, it is difficult to find the interaction discipline directly. This paper analyzes the intrinsic interaction laws based on the phenomenon characteristics, further reveals the evolutionary mechanism between transport infrastructure and economic distribution by derivation of the theoretical model, and proposes three dynamic evolution modes based on leading evolve mechanisms alternation.To further understanding the interactive evolution of transport infrastructure and economic distribution, combined with self-organization mechanism of urban economy development and organization mechanism of transportation construction, built mechanistic models based on three systems dynamic evolution modes by seeing the system develop stability as prerequisite, the rent level of land as economic indicator, the article simulated the model by differential equations stability theory,which reproduced the system evolution process under different hydrodynamic conditions and reflected the nonlinear characteristics of system crossfeed development, revealing the existence of evolve direction differences and fluctuation stability characteristics under different development mechanism, verified the significant impact that interventions bring to the system evolution, The evolution concept of transportation infrastructure and economic distribution comprehensive system has been established initially.However, the aim to build the system evolution concept is not only to know the process of system evolution, what more important is to identified the coordination between transportation infrastructure and economic distribution. But it is difficult to find the development stage directly due to the implicit relationship of system power alternating. The article identified a subsystems coordination model, using Zipf distribution of economy and fractal dimension of traffic networks, clear the evolution stage of the system mechanism and effectively predict the future direction of system evolution. On the one hand, clear the relationship between demand and supply of the city to distinguish the healthy development of the city, on the other hand, provide decision making basis to the government.At last, based on the identification of system coordination, clarified the interaction phase between transport infrastructure and economies distribution patterns, which leading the effective decisions on transportation infrastructure investment. According to this idea, based on macro-economic models and fractal principles, the article proposed two decision-making methods to optimize the trunk traffic channel programs and regional investment structure. The former focuses on the importance of the trunk traffic channel, building portfolio decision model to propose a preferred embodiment of the trunk traffic channel, combined with the economic benefits and contribution capacity to the economic morphology evolution that trunk scheme takes. The latter builds a regional transport infrastructure investment structure optimization model based on self-regional and inter-regional induced economic growth that transportation infrastructure generated, by defining maximum economic benefits of regional investment as objective function, considering the constraint of economic distribution pattern coordinate evolution. Both models make transportation investments to meet the regional maximum economic benefits and guide regional economies distribution pattern evolves towards a more coordinated direction at the same time. Simulated by Chengdu statistics, the numerical simulation results verified the validity of the model and algorithm, the conclusion has strategic reference value to the transportation infrastructure investment decisions.