Study Of Cascading Failure Model On Traffic Networks

Various traffic networks play an important role in daily life and have different topological characteristics such as small-world and scale-free.The factors of traffic congestion,natural disasters and traffic accidents may cause some station failures,which will lead to the cascading failure,resulting in large-scale network paralysis.Therefore,the in-depth study of the cascading failure phenomenon in traffic networks can provide theoretical references for the safe operation of traffic systems.The main research contents and research results are as follows:Considering that when cascading failures occur in traffic networks,the load redistribution usually has characteristic of power-law(that is to say,when a station is broken,the great majority of passengers would evacuate to the nearby stations,but the very few would evacuate to further).We study the cascading failure model with powerlaw load redistribution under three kinds of attacking strategies(removing single node according to the load,removing multiple nodes according to the load and randomly removing multiple nodes)for different network structures(regular networks,WS smallworld networks,random networks and BA scale-free networks).Finally,we confirm the robustness of our results by further performing simulations on real-world traffic networks.The results show that:(1)the robustness of BA scale-free networks is stronger than other networks when the load redistribution range tends to be local under removing single node according to the load;(2)the network robustness increases with the increase of the load control parameter α under randomly removing nodes,while this conclusion is not applicable to the case of removing nodes according to the load;(3)the more global the load redistribution range,the stronger the network robustness.Take Chongqing,Chengdu,Kunming,Guiyang and Lhasa for examples,we further study the cascading failure model with load redistribution based on the nearest neighbors,and bus stop network robustness is studied when the node fail based on the number of lines at a station.The results are compared with the widely studied random failure,degree-based attack and betweenness-based attack.It includes the following three aspects: network topological characteristics analysis,static robustness analysis under different nodes failure modes,and dynamic robustness analysis based on the cascading failure model.The results show:(1)the cumulative degree distribution and the cumulative distribution of the number of lines at a station in each city approximately obey the exponential distribution;(2)the static robustness of the bus stop network is closely related to the network topological characteristics,the greater exponent of the cumulative degree distribution,the worse the robustness on the network under degreebased attack;(3)in contrary to results of static robustness,the destructive to the network in dynamic degree-based attack is less than that in static degree-based attack when cascading failure is considered.