Multiobjective environmentally sustainable network design using Pareto optimization

Abstract

To control the environmental deterioration and enhance the environmental sustainability of transportation systems are pressing subjects for governments and transportation authorities nowadays. To this end, a more realistic and systematic modeling, evaluation, and design framework with environmental sustainability is particularly urged. In this paper, a bi-level transportation network design problem with multiple environmental considerations is investigated. To explicitly reflect various requirements of environmental sustainability from planners, total emissions costs and total excessive cost are minimized along with total system travel time while performing optimal capacity expansion. To leave space for additional information on decision-making for planners and provide more generalized description of solution optimality, Pareto optimization approach is adopted. The study proposed a multi-objective variant of a new meta-heuristic named Chemical Reaction Optimization (CRO) as the optimization tool to solve the formulated network design problem. Well-constructed Pareto sets have been successfully acquired for each scenario tested using Sioux Falls network. The result shows that there are different conflicting relations between pairwise objectives under different demand situations and the newly proposed multi-objective metaheuristic succeeds to produce approximations of Pareto front with comparable quality to NSGA-II with less runtime for the considered road network.