Characteristics Analysis And Hub Identification Of Urban Public Transport Complex Network

As a component of urban infrastructure,urban public transportation is not only the main way for residents to travel,but also an effective means to alleviate urban traffic congestion and ensure sustainable development.With the acceleration of urbanization,major cities have generally formed a relatively mature public transport network,and some large cities have even formed a multi-mode public transport system based on subways and conventional public transport.In the background of public transport integration,in order to objectively and comprehensively grasp the nature of urban public transport system,this paper studies the structure characteristics of public transport network based on the complex network theory.Based on this,a method of bus hub identification is proposed,which is expected to provide scientific basis for public transport planning,construction and operation management.First,considering the spatial connection relationship and supply performance differences between conventional buses and subways,a Space-L weighted network model for the expression of composite bus network structure is proposed.Based on the mapping relationship between bus stops and network nodes,the theoretical and practical significance of the statistical indicators of the network model is explained.Secondly,taking Xi’an City as an example,construct a composite network model and carry out structural characteristics research.The result shows: the degree distribution of public transportation network follows exponential distribution which is in the dynamic process of transforming to scale-free network and there is “Matthew effect” in the development of network;in the context of multi network,conventional bus stops play an important role in serving bus travel connection,while metro stations play an important role in serving bus capacity turnover;the average shortest distance of the composite bus network is 13.27% lower than that of the conventional bus network,which means the loading of the subway network strengthens the network connectivity;Wulukou,North Street,Dayan Pagoda and Weiyang Road,Keji Road,Zhangba East Road,South Second Ring Road are particularly important in improving public travel efficiency.By comparing Xi’an with other big cities,it is found that the number of bus stops is large,but the cohesion between stops,network connectivity and bus travel efficiency are low,and the line network needs to be optimized.Based on this,some suggestions are put forward for the development of public transportation in Xi’an.Finally,in order to quantify the functional strength of hub sites relatively objectively and comprehensively,a new type of hub identification index called CFI which takes degree,strength,betweenness and closeness centrality as evaluation factors is proposed,and the algorithm for solving the index is established based on grey correlation analysis and entropy weight method.On this basis,combined with system clustering analysis,the method of station classification and hub identification is proposed.Taking Xi’an public transport network as an example,the CFI of each station is calculated and its effectiveness is verified.It is pointed out that there are86 hub stations of different levels in the research area,and the characteristics of each grade of hub are analyzed.