Role of Asphalt Pavements in Achieving Net-Zero Emissions in the US Transportation Sector

Abstract

Transportation in the United States is the leading sector for greenhouse gas (GHG) emissions, with its contributions increasing over the years. To achieve the US goal of net-zero emissions in 2050, the Federal Highway Administration has launched several programs to set goals and strategies for reducing the emissions in the transportation sector. Flexible pavements, an integral part of the transportation system, contribute significantly to the sector’s carbon footprint. This study investigates the carbon reduction strategies of various states (Florida, Illinois, New York, Pennsylvania, New Jersey, Massachusetts, California, Texas, South Dakota, and Alaska). In addition, life cycle assessments (LCAs) were conducted to quantify the contribution of asphalt concrete pavements toward the states’ goals. The LCA results, calculated for a lane-mile of pavement, considered materials, construction, maintenance, rehabilitation, and use stages. The results showed that the New Jersey pavement section had the highest energy consumption over its life cycle, while Illinois had the lowest. In addition, the maintenance and use stages accounted for a significant portion of the overall GHG emissions, contributing an average of 92% of the total energy consumed. These impacts were primarily influenced by the pavement’s condition, specifically its roughness and volume of vehicles traveling on it. While current transportation emission reduction strategies focus on curtailing on-road vehicles emissions, this study highlights the significant contributions of pavement structures to overall GHG emissions.