Message from the Director

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I am inspired by NAPA’s vision for net-zero carbon emissions for the asphalt industry. If you haven’t heard about these aspirational goals to help halt climate change, I encourage you to visit asphaltpavement.org/climate. 

Reaching these goals won’t be easy; in fact, it’s the opposite. Experts say we’ll have to limit the rise in global average temperatures to under 2°C (3.6°F) above preindustrial levels—and ideally, under 1.5°C (2.7°F) by 2050. To achieve this, global energy-related CO2 emissions will have to be reduced to 1.7 tons of CO2e per person per year. To put this number into perspective, the U.S. carbon footprint related to energy is around 16 tons of CO2e per capita, which means Americans will need to cut their emissions by almost 90%. That goal has been described as a “moonshot”, relating it to the mission of my father’s generation to put mankind on the moon and bring them home safely.

All sectors of the economy will have to make changes. According to the EPA, the transportation sector is the largest contributor to anthropogenic U.S. greenhouse gas (GHG) emissions, accounting for 29% of total GHG emissions. It’s encouraging to see large and small companies step up to the plate and commit to net zero by 2050.

The pavements community has an important role to play. Stakeholders in the private and public sectors must work together and commit to slow global warming. NAPA’s vision includes four goals for the industry to achieve by 2050— 

  1. Achieve net zero carbon emissions during asphalt production and construction. 
  2. Partner with customers to reduce emissions through pavement quality, durability, longevity, and efficiency standards. 
  3. Develop a net zero materials supply chain. 
  4. Reduce electrical intensities and transition to electricity from renewable energy providers.

Early strategies will include substantial reductions in energy used to produce asphalt paving mixtures, big increases to RAP contents, better utilization of locally available aggregate sources, cold recycling, and also building longer lasting pavements. To substantially reduce energy, contractors must reduce stockpile moisture contents, invest in other well-documented energy saving technologies at plants, and use WMA to reduce mix temperatures by 50°F or more for all mix production, not just some of the time.

Nationally, the average RAP content in new asphalt mixtures has plateaued over the last few years at about 21%. Although that’s a percentage to be proud of, we can do more. For years, Japan and the Netherlands have been averaging at about 50%. In the U.S., we have the technical capability to achieve 50% RAP; NCAT has several case studies demonstrating that high RAP content mixes can be even more durable than traditional, moderate RAP content mixes or virgin mixtures. Surprisingly, there are several owner agencies, big and small, who still explicitly prohibit RAP in certain mixes. Implementing balanced mix design and quick and simple performance tests as part of quality assurance is a key to unlocking higher RAP contents and other innovative technologies that will assure that paving mixtures of tomorrow are durable, economical, and sustainable.

The net zero vision for asphalt pavements isn't just about emissions generated during construction, it’s about their full life cycle, including the GHG generated by vehicles during the “use phase” as well as when the pavement requires rehabilitation. Accounting for emissions in all phases of a pavement’s life will require a life cycle assessment. Over the next few years, growing efforts will develop the data associated with production of raw pavement materials, their transportation to the project, construction activities, estimating emissions from vehicles as we transition from internal combustion energy to battery or fuel cell powertrains, and finally, dealing with the pavement materials when rehabilitation is needed.

One thing is certain, we can’t wait any longer to act. Although we don’t have all of the steps worked out, we can and we must begin to make the changes we know can move us in the right direction for the sake of future generations. 

Randy C. West, Ph.D., P.E. | Director and Research Professor