Optimization of congestion pricing road network with variable demands

This paper addresses a new optimization scheme designed for a congestion pricing road network with variable demands (CPRAM). A congestion pricing road network with variable demands can be formulated as a mathematical program with equilibrium constraints (MPEC) where the user equilibrium with variable demands is expressed as a variational inequality problem. Due to the non-differentiability of the perturbed solutions in equilibrium constraints, a non-smooth optimization model is established. A generalized bundle subgradient projection method (GSP) is presented to solve the CPRAM with global convergence. Numerical calculations are conducted on a small-scale road network and encouraging results are reported.