The Research On The Optimization And Application Of Medium And Small Urban Freight Transportation Network Based On The Bi-level Programming Theory

Accompany with the speeding process of our economic development and the advancementof urbanization,the urban traffic problem is increasingly highlighted, continuously restricting thesustainable development of urban economy and transportation, seriously affecting thedevelopment of the city and people’s life. Urban freight transportation system as an importantpart of urban transportation system, it constitute the important foundation of the urbancomprehensive development, and play a key role of promoting urban economic development andimproving urban traffic problems. So it is necessary to take the system balance and sustainabledevelopment concept into the research of urban freight transportation planning and management,and planning layout and optimizing construction of urban freight transportation networkscientifically and effectively, therefore promots the development of urban economy and trafficharmony and sustainably.This article through to the analyses of the characteristics of medium and small urban freighttransportation development in our country, In combination with the basic theory of bi-levelprogramming and mathematical statistics analysis method of principal component analysis andclustering analysis, and establishes the evaluation index system of medium and small urbanfreight transportation network, and do study on analysis and research combined with examples,and then puts forward measures and suggestions of network optimization.First of all, this article dissects the current development characteristics of medium and smallurban freight transportation, summarizes the main problems existed in urban freighttransportation and then reflects deeply on it, the research induces, consolidates and analysis theresources characteristics that affect the development of urban freight transportation, puts forwardto the trend of the medium and small urban freight transportation development combined with thedevelopment direction and goal of urban freight transport.Secondly, this article summaries and analyses on the basic theory of bi-level programming,states the application、research ideas and processes on medium and small urban freighttransportation, and makes a detailed summary and analysis on the application of principalcomponent analysis and cluster analysis which in the small urban freight transportationnetwork optimization combining with the SPSS software.Once again, on the basis of the principle, method and target of the indicator system, thearticle establishes the evaluation index system of medium and small urban freight transportationnetwork from three layers of target, principles and index, then calculates and analysis all theindicators from the indicator system, and divides and classifies all the indicators accordding tothe different requirements of supply and demand. Finally, this article selects sample cities to collect, process and analyze the datas accorddingto the content of the indicator system. In combination with the basic theory of bi-levelprogramming, make the research of principal component analysis and cluster analysis by usingSPSS software, and test the reasonableness of the output. At the same, the article puts forward theoptimization measures and suggestions of medium and small urban freight transportationnetwork combined with the results of the analysis.