Contribution of climate change and traffic load on asphalt pavement carbon emissions

The maintenance and rehabilitation of asphalt pavement contribute to carbon emissions, impacting climate change. The interaction between climate change and increasing traffic loads influences the frequency of maintenance for asphalt pavement infrastructure. This study assessed the combined impact of climate change and traffic growth on the performance and carbon emissions of Chinese freeway asphalt pavement, informing carbon reduction policies amid future climate change. Using climate prediction models (Representative Concentration Pathways 4.5 and 8.5), the research forecasted pavement performance under 2% and 4% traffic volume growth rates and estimates future carbon emissions based on maintenance strategies. Results indicated that both future climate change and increased traffic loads would have adverse effects on the asphalt pavement performance, particularly with a 4% annual traffic load growth. Freeway length with rut depths exceeding 25 mm may increase from 33,600 km in the 2020s to 94,950 km in the 2050s (an 182.6% increment). The interaction between climate change and traffic growth intensifies pavement deterioration, increasing maintenance frequency and carbon emissions. Under the conditions of RCP 8.5 and a 4% traffic load growth rate, the carbon emissions in the 2050s may increase by 71.9 million tons compared to the 2020s (an 180.7% increment). This underscores the need for strategic interventions and policy decisions to mitigate environmental impacts.