Identification method of dynamic road traffic network vulnerability

The trfffc flow propagation process of section and node and the discrete instantaneous dynamic equilibrium condition of optimal route choice for user were analyzed,the reactive traffic flow model of dynamic user equilibrium network was established,diagonalizable heuristic algorithm was designed to solve the model,and the dynamic vulnerability index of road network was evaluated.Analysis result shows for an example road network with 12 sections and 9nodes,free-flow speed is 40km·h-1 and jam density is 125veh·km-1,when section 1is broken at time 3,vehicle amount at peak time increases from the original 50 veh to 100 veh at section 3,the inflow of section 3increases by 1time,and the inflow of section 2drops to 0.The damage of section 1doubles the vehicles on the path consisting of sections 3,6,7and 10,the increase of vehicle amount leads to the increase of impedance on each section.The traffic flow propagation process of vehicle bypassing the broken section can be described,the proposed method is effective to identify the vulnerability of road network for each section at each time.3tabs,11 figs,25refs.