The flourishing complex network theory has aroused increasing interest in studying the properties of real-world networks. Based on the traffic network of Chang-Zhu-Tan urban agglomeration in central China, some basic network topological characteristics were computed with data collected from local traffic maps, which showed that the traffic networks were small-world networks with strong resilience against failure; more importantly, the investigations of assortativity coefficient and average nearest-neighbour degree implied the disassortativity of the traffic networks. Since traffic network hierarchy as an important basic property has been neither studied intensively nor proved quantitatively, the authors are inspired to analyse traffic network hierarchy with disassortativity and to finely characterize hierarchy in the traffic networks by using the n-degree–n-clustering coefficient relationship. Through numerical results and analyses an exciting conclusion is drawn that the traffic networks exhibit a significant hierarchy, that is, the traffic networks are proved to be hierarchically organized. The result provides important information and theoretical groundwork for optimal transport planning.

中文翻译：

---

交通网络的层次属性

蓬勃发展的复杂网络理论引起了人们对研究现实世界网络特性的兴趣。以华中地区长株潭城市群交通网络为基础，利用局部交通地图数据计算出一些基本的网络拓扑特征，表明该交通网络是具有较强抗故障能力的小世界网络；更重要的是，对分类系数和平均最近邻度的研究暗示了交通网络的不协调性。由于交通网络层次作为一个重要的基本属性，既没有深入研究也没有定量证明，作者的灵感来自于分析具有不协调性的交通网络层次结构，并通过使用 n 度-n 聚类系数关系来精细表征交通网络中的层次结构。通过数值结果和分析得出一个令人兴奋的结论，即交通网络表现出显着的层次结构，即证明交通网络是分层组织的。结果为优化交通规划提供了重要的信息和理论基础。