A meta-heuristic approach for solving large network design problems

This paper proposes an optimisation model and an evolutionary algorithm for solving large network design problems; the proposed method can be adopted for solving urban and extra-urban network design problems. This paper focuses on the urban network design problem which is more difficult to solve than the extra-urban one. The problem in question consists in optimising the configuration of road networks by designing flow directions of existing roads and signal settings at intersections. A non-linear constrained optimisation model for solving this problem is formulated, adopting a bi-level approach in order to reduce the complexity of solution methods and calculation times. A scatter search algorithm is proposed and tested on a trial and on a real dimension network. Initial results show that the proposed approach allows local optimal solutions to be obtained in reasonable calculation times also on real dimension networks.