A traffic assignment model considering individual utility under network vulnerability perspective
In response to the issue of nonlinear mutations and increased vulnerability of urban traffic networks caused by disturbances such as emergencies, traditional allocation methods based on expected travel time or deterministic impedance are unable to reflect the differentiated preferences of travelers for reliability and delay risks. This paper, from the perspective of road network vulnerability, introduces the description of traffic impedance under event influence, constructs a user allocation framework considering individual utility differences, and validates the normal and vulnerable states on a sample network with 6 nodes, 10 road sections, and 5 pairs of origins-destinations. The results show that the effective paths for the same OD pair satisfy the equilibrium characteristics of equal travel time budget and the minimum value, and the model solution is reasonable; different types of travelers exhibit differentiated flow allocation in both states, indicating that considering heterogeneity helps to depict the distribution law of traffic flow in vulnerable scenarios. The research can provide a reference for traffic organization and road network optimization under emergency conditions.