Combined model and algorithm of expanding network capacity and road pricing

Authors study the integrated problem of expanding network capacity and road pricing. A bi level programming model is formed. The upper objective of the model maximizes net benefit of network, while the lower is the stochastic user equilibrium model with elastic demand. Because of complex property of solving bi level model, a heuristic algorithm which is based on step acceleration method and penalty function method is proposed, and in the end,a numerical example is given.