Abstract: Accurately assessing the vulnerability of road networks is the basis of road planning. The congestion effects of road sections and intersections are considered. The concept of bottleneck lines is introduced to identify the vulnerable line, it is difficult to withstand emergencies due to small road capacity. A road network vulnerability analysis method based on spectral analysis is proposed thereafter, using the minimum segmentation theory of the spectral partitioning to locate the bottleneck line. In addition, in order to solve the problem of large-area cut-off segmentation, a road network improvement measure based on connectivity contribution is proposed, providing improvement suggestions for road network protection. Simulations show that the proposed method is more accurate in locating the bottleneck line compared to comparison scheme, and the network improvement measure can effectively avoid the segmentation phenomenon of the road network.

Key words: road traffic network, vulnerability analysis, spectral analysis, bottleneck line, cut-off segmentation