Study On The Highway Network Structure Optimization Theory And Methods

Since the reform and open, the highway traffic of our country has got quite great development, the infrastructure has been improved obviously, the transportation capability has been strengthened markedly, and the highway traffic adapts to the national economy and the social development more and more. Yet with highway heads for networkization and systemization gradually, construction contradiction existing in the highway infrastructure is also increasingly outstanding, and needs to be solved. Therefore, for solve the function structure unreasonable problem which exists in the process of the highway network development and construction, this article from the views of highway network's functional hierarchy division, rational scale, grade structure optimization and the optimization effect evaluation, aimed at giving full play to the network efficiency of the highway network, achieving its economic and social maximum benefits, established the highway network structure optimization theory method system which provided scientific guidance for the next step of the highway construction and development for better adapting to the traffic and economic development needs of the new era. The specific research results are as follows.According to the current structure problems of the highway network, the article proposed the highway network structure optimization's basic concept and the connotation on the basis of analyzing highway and highway network's characteristics and functions, analyzed social economic request to highway network functions and structural optimization. Basing on the value analysis, using the logical thinking of 'Values-Goals-Objectives-Criteria and Standards', discussed the determination method of the region highway network structure optimization's goal and the emphasis of the regional highway network structure optimization.With analyzing the corresponding relation between the hierarchy-need theory and the highway network demand, analyzed influencing factors and classification methods of the highway network functional classification from the angle of traveler demand, external environment and highway network itself. And combined with the study of'nodes' characteristics, based on the use of self-similarity theory and cluster analysis etc., researched the concrete methods of the highway network's functional hierarchy division, put forward the highway network function AHP method which based on the important degree of functional-based sections.Basing on the analysis of functional hierarchy, nodes of different levels and the regional highway network's connectivity, proposed the stratified node connectivity method to determine the ideal form of highway network's development scale. In the mean time, from the view of adaptation for the economic development, analogy other countries'highway network development mileage, through the analogy which based on the analysis of the growth process to determine the highway network's reasonable scale within a steady-state time and different developing stages.Through researching the relationship between our country's three highway classification methods, qualitatively analyzed the results of the highway network grade structure optimization. And basing on functional classification, applied multi-objective function and orthogonal enumeration method, optimized the highway network's grade structure from macroscopic and microscopic aspects. At the same time, established multi-objective programming model which was based on the maximum capacity, the maximum operating efficiency and the highest technical level, and studied the Matlab's application of the model solution.Corresponding to the basic concept and the content of highway network structure optimization, builded the optimization effect evaluation index system from the technical, economic and social evaluation's perspective. And basing on fractal theory and the comprehensive evaluation method, studied the method of the highway network structure optimization effect evaluation which focus on the functionality, services and hierarchical structure, etc..Took shaanxi province as an example to verify the theory and method this article puts forward which applied in the regional highways network's structure optimization.