新建轨道线路对轨道网络效率及脆弱性的影响分析——以广州地铁6号线为例

Impact Analysis of a New Line on the Rail Transit Network's Efficiency and Vulnerability——a Case Study of the Guangzhou Metro Line 6

城市轨道交通网络的效率与脆弱性是衡量线网性能优劣的重要指标。为研究新建线路的接入对既有网络效率及脆弱性的影响,以广州地铁6号线为例,分析了6号线对广州市地铁网络造成的拓扑特性变化。运用L空间拓扑建模方法构造了有、无6号线的两个轨网模型,并选取了节点间最短路径长度和介数中心性两个指标来表征网络的效率和脆弱性,对上述2个轨网模型的相关网络拓扑指标进行对比分析。研究结果显示6号线接入轨网后提高了全网连通的效率,降低了网络脆弱性,且网络中既有站点、连边介数中心性的变化与6号线距离的远近密切相关。研究方法和结论值得交通规划和管理决策者在评估新建线路性能时参考和借鉴。

Efficiency and vulnerability of Urban Rail Transit Network are important indicators to measure the performance of the network. To study the impact of a newly constructed rail line on the existing network＇s efficiency and vulnerability, the Guangzhou Metro Line 6 is taken as an example, and how the Metro Line 6 changed the topological properties of Guangzhou Metro Network is analyzed. Two network models are established in L-space method, with and without Guangzhou Metro Line 6, respectively. And the average shortest path length between node pairs and betweenness centrality are selected to indicate the efficiency and vulnerability of the network, respectively. Finally the topological indicators of the above two network models are compared and analyzed. The results denotes that with the connection of line 6, the efficiency of the Guangzhou Metro Network increases and the vulnerability decreases, and that the betweenness centrality of the existing nodes and links varies closely related to the distance between these components and Line 6. The research methods and conclusions are worthy of considering by transportation planners and management decision-makers in assessing the performance of a new rail transit line.