地铁线网结构对连通可靠性影响评价

地铁是现代大城市最重要的公共交通系统之一,其线网连通可靠性不但受到运营故障、恐怖袭击、踩踏事故等不确定性因素影响,也与线网结构有密切关系.为评价线网结构(表示为网络的线路组成)对地铁线网连通可靠性的影响,基于传统的节点连通可靠度概念定义了“线路连通重要度”新概念及其计算模型,即线路增减/失效前后网络平均连通可靠度的变化(百分比).采用基于排序的ORDER 方法和网络连通判断算法求解上述模型.以广州规划年地铁线网为例验证了所提模型的有效性,并分析了地铁线路特征(站点类型和数量)对网络连通可靠性的影响.结果显示,3号线的线路连通重要度最大(99.84%)为关键线路.研究发现而线路连通重要度受到线路中换乘站数量和中间站数量的综合影响,且前者的影响高于后者.研究结论值得交通规划和管理决策者在制定地铁建设和维护优先政策时参考和借鉴.

An Evaluation of the impact of metro structure onto the reliability of Network Connectivity

Metro is one of the most important public transport systems in modern society.The reliability of connec-tivity is not only affected by uncertain factors (e.g.operational failures,terrorist attacks,and stampedes),but also close-ly related to network structure.To evaluate the impacts of network structure (in terms of different composition of lines) on the reliability of the connectivity of the metro network,the concept of "the importance of line connectivity" and the corresponding models are developed to study the difference (in percentage)before and after line addition/removal based on the theory of the reliability of connectivity.An order-based algorithm integrated with a judgment algorithm is used to find solutions for the proposed models.Metro Network of Guangzhou in 201 5 (i.e.a typical grid network)is selected as a case study to evaluate the impacts of line features (e.g.number of stations)on the reliability of network connectivity.The re-sults show that the Line 3 consistently has the highest connectivity importance (reaching 99.84%).As a key line,its im-portance is jointly affected by the number of transfer stations and intermediate stations.The impact of the former is more significant than the latter.It is suggested that in-depth studies and evaluations should be carried out to prioritize the poli-cies related to metro construction and maintenance .