摘要：AbstractLink capacity enhancement is often used for relieving traffic congestion. However, this measure may not be efficient because it may move the congestion from one road to another. Therefore, an efficient scheme should take into account the effects of the changed network flow pattern to achieve a global optimal solution. In this paper, elastic demand network equilibrium with queuing assignment model is established to describe drivers’ route choice behavior under both queuing and congestion conditions. The improved inner penalty function method is put forward to solve the equilibrium model. Then the nondegenerate extreme point of path flow equilibrium solution is derived. Finally, sensitivity analysis is performed to derive the explicit expressions of equilibrium parameters with respect to changed link capacities. This sensitivity information can accurately check whether enhancing road capacities would be helpful to relieve traffic congestion by reducing traffic delays in saturated links. The derivative information also allows to estimate a nearby solution for small changes in the link capacity parameters once an equilibrium solution has been obtained. A numerical example is presented to explicitly demonstrate the sensitivity analysis method and its application to the evaluation of network capacities expansion schemes.
