Bi-objective network optimization for spatial and temporal coordination of multiple highway construction projects

Even though highway Construction and Maintenance (C/M) projects aim to improve transportation infrastructure and travel services, these highway C/M projects become one of the main reasons for causing traffic congestion on existing road transportation systems as well as traffic accidents in work zone areas. The number of work zones is increasing due to the aging infrastructure, which demands spatial and temporal coordination of these work zones for efficient use of the existing transportation network. Unlike other studies focused on the single C/M project level, this study deals with network-wide impacts of multiple C/M projects. This problem is formulated as a bi-objective multi-period transportation network optimization problem to seek an optimal schedule that coordinates multiple C/M projects. The objectives are to minimize the total system cost and to maintain minimum travel services between origins and destinations. A bi-objective genetic algorithm is employed to solve the multi-period network optimization problem. A numerical example shows that the optimal coordination saves more than 50% of waste in system costs, compared to the worst case scenario.