考虑级联失效影响的城市道路网络容量研究

Study on capacity of urban road network considering cascading failure

城市道路交通网络中,交通拥挤的传播会引起路网容量发生变化,同时,交叉口或路段容量的变化亦将影响拥挤传播的后果。因此,构建考虑拥挤传播影响的路网容量双层规划模型,下层模型为刻画城市道路交通网络拥挤传播过程的级联失效模型,上层模型确定一定服务水平下路网能承担的最大交通需求(即路网容量),其中路网服务水平根据路网阻塞程度评定。然后,基于迭代优化设计双层规划模型的启发式求解算法。最后,将该双层规划模型应用于一个简单的双层城市道路交通网络(上层为出行网络,下层为道路网络)中进行仿真试验,比较发现:1级联失效,也就是拥挤传播对路网容量有一定影响,且路网服务水平越低,对路网容量的影响越显著;2上层出行网络结构对道路网络容量存在影响,出行结构不同,路网容量不同。

In the urban road network,the capacity of road network will change due to the congestion propagation,while the variation of the section or intersection capacity also influences the congestion propagation. Therefore,a bi-level programming model of road network capacity considering congestion propagation is suggested. On the one hand,a cascading failure model is built to describe the process of the congestion propagation in the lower-level programming. On the other hand, the maximum traffic demand under the given network service is calculated in the upper-level programming,and the network service is measured by degree of road network congestion. Then,a heuristic algorithm is designed to solve the bi-level programming model. Finally,this model is applied to a simple urban bi-level network( upper-level network is the trip network,lower-level network is the road network) to prove the model and algorithm.Simulation results show that cascading failure( i. e. the congestion propagation) has a certain influence on the road network capacity,especially when the service level of road network is lower. Upper-level trip network has also effect on the road network capacity.