Carbon-emission calculation method during operation period based on asphalt pavement performance

Current vehicle carbon emission models tend to ignore the influence of road roughness on driving speed selection, which may damage the carbon emission evaluation accuracy. In this study, first, based on the results obtained with a portable emissions measurement system (PEMS), an explicit model for user vehicle carbon emissions, driving speed, and pavement roughness is established. Second, the influence of road roughness on driver behavior choice is investigated, and an interrelationship model between roughness and driving speed choice is developed. Finally, a more realistic carbon emission calculation model during the operation period is proposed based on the pavement performance model, and the accuracy is verified in comparison with the traditional vehicle operating cost (VOC) model. It is found that there exists a carbon emission minimization point under free-flow conditions, and the corresponding driving speed is the optimal speed point of user vehicles, i.e. 63 km/h. In addition, a great linear correlation exists between the roughness and driving speed selection, which should be considered in the final calculation model. The vehicle carbon emission model developed in this research provides solid references for evaluating the life-cycle emission of asphalt pavement and guiding the selection of maintenance strategies for the pavement to lower carbon emissions.