A subgradient optimization model for continuous road network design problem

This paper addresses a subgradient optimization model for a well-known continuous network design problem (CNDP). A continuous network design problem can be formulated as a mathematical program with equilibrium constraints (MPEC) where the user equilibrium flows are considered. By contrast to previous studies, in this paper, a conjugate subgradient projection method is presented to efficiently solve the continuous network design problem with global convergence. Numerical calculations are conducted on a real data of road network and various grid-size networks where encouraging results are reported when compared to earlier studies.