Time-dependent discrete road network design with both tactical and strategic decisions

This paper aims to model and investigate the discrete urban road network design problem, using a multi‐objective time‐dependent decision‐making approach. Given a base network made up with two‐way links, candidate link expansion projects, and candidate link construction projects, the problem determines the optimal combination of one‐way and two‐way links, the optimal selection of capacity expansion projects, and the optimal lane allocations on two‐way links over a dual time scale. The problem considers both the total travel time and the total CO emissions as the two objective function measures. The problem is modelled using a time‐dependent approach that considers a planning horizon of multiple years and both morning and evening peaks. Under this approach, the model allows determining the sequence of link construction, the expansion projects over a predetermined planning horizon, the configuration of street orientations, and the lane allocations for morning and evening peaks in each year of the planning horizon. This model is formulated as a mixed‐integer programming problem with mathematical equilibrium constraints. In this regard, two multi‐objective metaheuristics, including a modified non‐dominated sorting genetic algorithm (NSGA‐II) and a multi‐objective B‐cell algorithm, are proposed to solve the above‐mentioned problem. Computational results for various test networks are also presented in this paper.