Heuristics for urban road network design: Lane layout and signal settings

This paper concerns the urban road network design problem. In urban areas supply has usually been unable to keep pace with increasing demand: the only possibility is often to reorganise the current supply configuration in order to use existing resources efficiently. Thus, in urban areas signal settings and network topology (in particular lane layout) are the two major factors that can be handled by design models. Methods for the combined design of signal settings and topology are proposed in this paper. All the methods proceed in two stages: the first deals with integer variables (topology), while the second deals with continuous variables (signal settings). Some metaheuristics (Hill Climbing, Simulated Annealing, Tabu Search, Genetic Algorithms and Path Relinking) are specified for the topology design stage, and they are used singularly or jointly. The continuous part of the solution, with fixed topology is optimized through an algorithm for asymmetrical deterministic equilibrium assignment. This paper focuses on evaluating performances obtained by all the different algorithms proposed for the topology design stage. The algorithms are compared by applications to real networks, and some conclusions are drawn about their efficiency.