Research On Identification Of Critical Links And Protection Strategy Of Road Traffic Networks

In recent years,with the steady advancement of the systematic construction of urban road infrastructure,the urban transport network system has become increasingly complex.The widespread breakdown of the entire road system due to the failure of some sections is a common occurrence and poses a serious threat to the proper functioning of the road network,and the road traffic safety problem has become a hot issue of common concern for traffic management departments and passengers.In view of the various potential risks and contingencies in road operations,academics have mainly studied the safety of road traffic systems from the perspective of complex networks in terms of the system loss caused by the failure of key nodes,and some scholars have confirmed through simulation experiments that the adoption of certain protection measures for key nodes can effectively improve the overall network resistance to destruction.Therefore,this paper evaluates the importance of road links based on urban road network data and road traffic operation data,and constructs models of critical links identification and protection in road traffic network for specific analysis.This paper selects the roads in Guangming District of Shenzhen as the research object.Firstly,through the road network GIS data and traffic operation data,the road topology model and load network model are constructed.And analyses the topological characteristics of the road system and the spatial and temporal distribution of the traffic state of the road links in the load network from the perspective of complex networks.Then,according to the node topology potential field and HITS algorithm,a congestion propagation model is proposed to calculate the failure probability of the road links.On the basis of this model,the input-output model is used to evaluate the functional vulnerability of road links,and the controllability theory is used to evaluate the structural vulnerability of road links.The road links with high failure probability and serious failure consequences are identified as critical links.The research results show that the identification algorithm proposed in this paper captures the influencing factors of topology and function well,and achieves certain advantages compared with the traditional identification algorithm.Finally,improves the routing strategy in traffic assignment according to the identification results of critical links.Combined with the idea of capacity expansion,a critical link protection strategy model based on Bi-level programming is proposed,and the specific implementation effect of the protection strategy is analyzed from three aspects : algorithm convergence,passengers preference and protection threshold.