Multi-objective optimization of pavement preservation strategy considering agency cost and environmental impact

Road network requires timely maintenance to keep pavement surface in good condition for reduction of fuel consumption with the limited budget. This study focused on development of pavement preservation strategies in the road network considering multi-objective optimization of agency cost and environmental impact (in terms of CO(2)emission). Field data from long-term pavment performance (LTPP) database were used to quantify the impact of pavement preservation treatments (crack seal, chip seal, and thin overlay) on the changes of surface roughness. The emission rate functions of vehicles with respect to speed and pavement surface condition were developed using Motor Vehicle Emission Simulator (MOVES) with the updated tire rolling resistance coefficients. The multi-objective optimization problem was solved using the Simulated Constraint Boundary Model (SCBM) method. The final solution was recommended based on the minimized distance from the utopia point to the Pareto front. The results show that the optimization solutions are affected by the available budget, existing pavement condition, truck traffic, and unacceptable level of pavement roughness. For multi-objective optimization of minimizing both agency cost and CO2 emission, the recommended preservation treatments among different segments is a combination of crack seal and thin overlay in most cases. These findings can be used by highway agencies to make road maintenance decisions considering the tradeoff between agency cost and environmental impact.