EVOLUTION OF PUBLIC TRANSPORT NETWORKS: AN EMPIRICAL ANALYSIS

摘要

There have been many studies using complex network concepts to analyze the topological properties of public transport networks (PTN). Most of these studies viewed networks from a static perspective, but seldom considered the temporal evolution of PTN. This paper presents an empirical analysis of the topological properties of PTN based on the bus networks data of Shijiazhuang from 1996 to 2008. The results show that: (1) the degree distribution of PTN represents a transition from power-law to exponential scaling with time. In practice, it can be well fitted with a stretched exponential distribution; (2) PTN has small-world feature, which means that the average distance between the nodes is rather small and grows logarithmically slow with the network size; (3) PTN has large clustering coefficient and the mean clustering coefficient decrease regularly with time. The findings of this analysis suggest that the evolution of PTNs is driven by competition between preferential attachment and geographical constraints. The results can help us to understand the evolution mechanism of PTN and optimize the transit system in future.