Research On Urban Transit Network Structure Analysis And Transit Network Design

With the development of economy and the progress of society, the traffic demand of cities keep increasing and the number of vehicles in the city show explosive growth, which brings problems of serious traffic congestion, energy consumption, environmental pollution and noise pollution etc. Facing with the problems, the big cities build policies to restrict the growth of vehicles. The contradiction between increasingly large traffic demand and the lack of ability become more and more serious. The public transit is considered as an effective tool to resolve the traffic problem. The urban transit network is a huge complex system, and it is the fundamental part of transit system. However, the existing bus network structures is unreasonable, resulting in long travel distance, more transfer times and other problems, which poses bad impact on passengers’enthusiasm to use bus. Therefore, in order to give full play to the advantages of larger traffic volume and less pollution, it should take some deep research to the existing bus network and how to design an effective network. So, the in-depth analysis of transit network, the study on transit network evaluation and the method of network design are conducive to optimizing the transit network structure, so as to improve the operating efficiency of the public transportation system, enhance the competitiveness of the bus system.This paper takes transit network structure evaluation, design and optimization as research contents, which aims to improve the understanding of transit network structure, provide feasible plan, optimize transit network scientifically, and then providing theory support to transit network design and then improve the efficiency of transit systems. The specific contents are as follows:Firstly, basing on the urban transit network structure, graph theory and complex network theory are used to construct some indicators to analyze transit network features. The transit networks of Baoding, Jinan, Shijiazhuang, Suzhou and Beijing are analyzed by complex network theory. The results show that transit network degree follows a shifted power law distribution, and transit networks are assortative networks with obvious community structures.Secondly, the transit transfer factor has been studied. Three methods are introduced to calculate the transfer time between stations in the network. A method basing on Space P is proposed to calculate transit transfer time. The property of transfer is analyzed deeply. Four types of adding lines are tested on transit network, the results show adding lines between nodes with small degree can effectively reduce transit network transfers comparing large degree nodes, large transfer nodes and randomly. Incorporating the hypernetwork, the stochastic flow distribute model is built to simulate the impact of transfer distance on the flow distribution of transit network. A comprehensive evaluation system is established, which combines with the transfer facilities, transfer convenience and transfer comfort basing on gray theory. The results show our method can effectively evaluate the transit stations and can give a help to transit station optimization.Finally, the transit network design and optimization problems have been researched. The system analysis method is used to analyze the components of transit design cost and the impact of different transit lines layout. The difference between single line and several lines layouts have been studied. A transit network design method basing bee colony algorithm has been proposed, which take the total travel time and transfers as objective. A greedy algorithm is used to construct initial transit line set, and then a new bee colony algorithm is used to modify the initial line set. The Swiss Mandl network and Mumford networks are used to test the efficiency of algorithms. The results show the algorithms can create better transit line set and have better efficiency, which can be applied to large scale networks. Combining the role of line in transit transfer and line nonlinear coefficient, line evaluation indicator has been constructed which is used in Baoding transit network optimization. The results can meet the requirements.