Vulnerability Based Dynamic Road Transportation Network Design

In the daily operations,the traffic accidents,natural disasters,terrorist attacks and other anomalies will interfere the operation status of the transportation network.The transportation traffic vulnerability descripts the potential degradation of network performance which caused by anomalies destruction of network components,the research of transportation network traffic vulnerability can clearly recognize the impact of anomalies on the operations of the network.The combine of transportation network vulnerability analysis with the transportation network design will help to reduce the impact of anomalies on the network operations and ensure the network can still be reasonably maintained.This paper includes the analysis of transportation network vulnerability into the design of transportation network and construct the vulnerability dynamic transportation network design model.First of all,this paper defines the vulnerability of transportation network as the degree of network performance degradation which caused by the capacity loss segment with the impact of anomalies.Deepen the understanding of transportation network vulnerability through the contrast with reliability,risk,robustness and other concepts.Secondly,analysis the influence factors of transportation network vulnerability through the network topology,the uncertainty supply of network and the uncertainty demand of network,and constructs the segment vulnerability assessment indicators on the basis of network backup capacity and the average travel time of network from the impact of segment damage on the service capacity of network and the average travel time of network,and also gives the calculation method of the vulnerability index with the random supply.Thirdly,establish the vulnerability static transportation network design model by incorporating the vulnerability assessment indicators into the bi-level programming model network design,and design the solving algorithm by combining genetic algorithm and F-W algorithm.Finally,introducing the time factor into the static model,establishing the vulnerability dynamic network design model by reconstructing the objective function and the corresponding constraints in the static model,and extending the solving algorithm of the static model.The case study verifies the effectiveness of the vulnerability dynamic network design model through the contrast of the vulnerability static network design results and the nonvulnerability dynamic network design results with the vulnerability dynamic network design results.The analysis results show that the introduction of time factor describe the dynamic changes in the investment costs,reconstruction scale and travel demand of the transportation network,it can enhance the feasibility of the network design;the introduction of the vulnerability index in the model can effectively reduce the vulnerability of each segment in the network design scheme,and reduce the anomalies influences of the network operational performance,and could facilitate the establishment of a more stable and efficient transportation network.