When people drive along smooth asphalt roads, they usually don’t give much thought to how the materials used to pave a road impact the global environment. But they should. Using asphalt for road construction has environmental benefits, improves fuel economy, and stores the building blocks for future roads.
Warm-mix asphalt technologies, which allow asphalt to be produced and placed at lower temperatures, save energy and reduce the production of greenhouse gases. Pavement mixes that use roofing shingles, tires, and even material reclaimed from roads reduce the carbon footprint of road building. They also save landfill space. With reclaimed asphalt pavements, the old binder in the road can be reactivated, reducing the need for virgin asphalt cement. In fact, when an old asphalt pavement is removed, 99 percent of the time it is recycled or reused. Open-graded road surfaces and full-depth porous asphalt pavements can help manage stormwater runoff and even help improve water quality.
And even without these innovations, the amount of energy required to produce and the amount of greenhouse gasses created during production are much smaller for asphalt pavement in comparison to alternate paving materials, such as portland cement concrete.
Finally, since asphalt pavements are smooth and flexible, tires rolling across asphalt encounter less resistance than on other types of pavements. This improves fuel economy and leads to quieter, more enjoyable rides. For more information on rolling resistance, see NAPA Special Report 205 and "Asphalt Pavement Smoothness: Quantifying the Environmental Impacts" (Asphalt Pavement Sept./Oct. 2012).
For more information about the sustainability of asphalt pavements, download a copy of Black and Green: Sustainable Asphalt, Now and Tomorrow. Or visit NAPA’s page on sustainability publications.