为深入分析城市交通网络拥堵动态演进过程,建立了交通拥堵传播的改进SIS模型(传染病模型)。模型根据目标节点自身受随机因素的影响、其邻居节点的状态和影响能力以及不同状态节点间的耦合强度,动态计算目标节点由畅通变为拥堵又恢复畅通的概率,并进一步考虑了不同交通状态的传播时间对拥堵传播的影响。基于BA(Barabási-Albert)无标度网络对传播过程进行仿真,拥堵随时间的演化与相关研究一致,验证了模型的有效性。仿真结果表明:根据作用节点属性的不同,随机因素对拥堵的初始规模、传播速度及传播稳定状态的阻塞水平具有不同的影响能力;不同状态节点间的相互作用对拥堵传播具有重要作用;畅通状态与拥堵状态平均传播时间的比值对拥堵传播的影响存在阈值;不同状态传播时间的波动性对拥堵传播速度、平衡态阻塞水平具有一定影响。
: In order to deeply analyze the dynamic evolution of urban traffic network congestion, an im- proved SIS model of traffic congestion propagation was established. The probabilities of an unimpeded node changing to congested one and then recovering unimpeded one were dynamically calculated accord- ing to the random factors' influence on it, the conditions and influence abilities of its neighbor nodes and the coupling strength of nodes with different conditions. Moreover, the influence of propagation time of different traffic states on the propagation was considered in this model. Simulated based on BA scalefree network, the evolution of congestion over time was concordant with relevant researches, which verified the effectiveness of this model. The simulation results show that the influence of random factors on initial size of congestion, propagation speed and congestion level at steady state is different according to node properties; the interaction between nodes with different states plays an important role in congestion propagation; the influence of ratio between propagation time of unimpeded state and congestion state exists threshold; the volatilities of propagation time under different states have a certain influence on congestion propagation speed and congestion level of equilibrium state.