How Asphalt Pavement Industry Will Decarbonize

In a follow-up to its 2022 GHG Emissions Inventory for Asphalt Mix Production in the United States, the National Asphalt Pavement Association (NAPA) provides a comprehensive roadmap for reducing greenhouse gas (GHG) emissions from asphalt pavements.

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After the National Asphalt Pavement Association revealed the Road Forward initiative in 2022, along with its comprehensive industry emissions inventory, a huge list of partners from all corners of the asphalt pavement world signed on as partners, all committed to decarbonization by 2050. However, one of the biggest question marks has continued to be exactly how the industry would achieve their ambitious goals. Today, the association unveiled its roadmap. 

A New Report

In the the newly published report The Carbon Footprint of Asphalt Pavements: A Reference Document for Decarbonization (SIP 109) NAPA reveals the proactive steps necessary for the industry and agencies to employ, taking advantage of the unprecedented federal funding set forth in the Infrastructure, Investment, and Jobs Act (IIJA) of 2021, the Inflation Reduction Act (IRA) of 2022, and other federal programs to reduce GHG emissions.Screenshot 2024 04 10 At 10 21 24 AmFrom NAPA website.

“The release of this report is impeccably timed,” stated Heather Dylla, Ph.D., Vice President of Sustainability and Innovation at Construction Partners, Inc. “Coinciding with the recent launch of the FHWA’s Low Carbon Transportation Materials Program Grants, this report emerges as a critical resource for agency engineers and asphalt mix producers alike. It holds the potential to foster vital discussions and collaborations across the industry, propelling us toward collective sustainability goals.”

One of the key points from the new report deals with targeting the existing technology and/or best practices already available to the industry that can be adopted now or enhanced, if already in use, to further reduce GHG emissions. Things like increasing the amount of reclaimed asphalt pavement (RAP) are a good place to start.

According to data published by NAPA and the FHWA, the national average RAP usage remains around 22 percent. However, asphalt mixes that include 50 percent RAP have shown a reduction in cradle-to-gate (A1-A3) emissions by 29 percent when compared to a mix without RAP.

Actionable Items

The intended audience for the new report includes pavement engineers, asphalt mix producers, paving contractors, policy makers, and other stakeholders with an interest in reducing embodied carbon emissions associated with asphalt pavements. According to a press release from NAPA about the report, here is a summary of some specific actions that can be taken:

  • Industry-Driven Opportunities: This section outlines various opportunities for asphalt mix producers and paving contractors to reduce GHG emissions. Readily available actions to reduce emissions associated with asphalt mix production include adoption of energy efficiency measures, switching to cleaner fuels, use of recycled materials, and use of biobased materials that capture and store carbon dioxide as a functional component of asphalt pavements. Pavement construction and maintenance activities are another opportunity to reduce emissions through improved construction practices that extend the life of asphalt pavements, improved smoothness to reduce vehicle fuel consumption, and flexible construction scheduling to reduce emissions associated with work zone congestion.  
  • Sources of GHG Emissions: Authors identify the major sources of GHG emissions throughout the entire life cycle of asphalt pavements, including raw material manufacturing, transportation, asphalt mixture production, pavement construction, use of pavements, maintenance and rehabilitation, and end of life. ​

    • Agency-Driven Opportunities: Recognizing industry cannot decarbonize without the cooperation and leadership of agencies and road owners, the report offers guidance on implementing pavement design considerations, specifications, and maintenance practices that prioritize sustainability pavement design considerations. These include incentivizing the use of materials with lower embodied carbon while allowing flexibility for contractors to innovate and prioritizing maintenance to ensure pavement smoothness to reduce vehicle fuel consumption, among others. 
    • Tools for Quantifying GHG Emissions: Authors summarize key tools already available to industry and agencies, such as environmental product declarations (EPDs) and life cycle assessment (LCA) software, that can help quantify GHG emissions and inform decision-making processes. ​

    Screenshot 2024 04 10 At 9 50 26 Amfrom NAPA report.Why The Report Is A Big Step

    “This report details actions asphalt mix producers and laydown contractors can take to reduce the carbon footprint of the pavements we construct while making our businesses better,” said Ron Sines, P.E., Vice President for Sustainability & Decarbonization at CRH Americas Materials, Inc. “It highlights the need to collaborate with owners on project designs and specifications to ensure innovations in materials and processes are employed quickly, maximizing their benefits. Most importantly, the report stresses the need to consider the entire asphalt pavement life cycle to ensure the best decisions are made from a decarbonization perspective.”

    The report’s authors – Director of Sustainable Pavements Joseph Shacat; Vice President of Engineering, Research, & Technology Richard Willis, Ph.D.; and WAP Sustainability Director of LCA Technology Ben Ciavola, Ph.D. – emphasize the importance of collaboration between industry, agencies, and academia to advance these strategies. ​ They also highlight the need for further research to better quantify and reduce emissions associated with asphalt pavements. ​

    “This report serves as a critical resource for the asphalt pavement industry and other stakeholders in their efforts to lower emissions toward decarbonizing infrastructure,” said NAPA President & CEO Audrey Copeland, Ph.D., P.E.​ “By implementing the recommendations outlined in this report, and furthering research to fill gaps, we can make significant progress toward achieving a sustainable and resilient transportation system.”

    Download the report here: , The Carbon Footprint of Asphalt Pavements: A Reference Document for Decarbonization (SIP 109)