Well-maintained roadways improve fuel efficiency
Most people know that properly inflated tires can improve a vehicle’s fuel efficiency, but did you know that properly maintained roadways can improve fuel efficiency across an entire pavement network?
“We are moving into a new era of pavement management systems, which consider not only rider comfort and safety but also the quantitative carbon environmental impact,” says MIT professor of civil and environmental engineering Franz-Josef Ulm, faculty director of MIT’s Concrete Sustainability Hub (CSHub) in an interview with Engineering News-Record (ENR) magazine.
A recent collaboration between the CSHub and the California Department of Transportation (Caltrans) showed that phenomena associated with pavement-vehicle interaction (PVI), including roughness and deflection, accounts for 1 percent of overall fuel consumption on California highways.
“While a passenger car wouldn’t achieve significant gas savings, road stiffness could make an enormous difference for 40-ton trucks, with up to 4 percent gas mileage savings," Ulm told ENR. “If we can save 2 million tons of CO2 per year, at the aggregate level, this becomes extremely important in a low-carbon economy.”Sustainability Hub
For the research, Caltrans provided the CSHub with a wealth of data collected using ground-penetrating radar. The data identified the road’s structure, including the materials beneath the pavement, and included GPS coordinates on every crack, rut, and bump in California’s 50,000 lane-mile system.
CSHub researchers employed a novel small-scale experimental approach in which a rigid steel tire rolls along a polymer pavement while they measure the horizontal force required to move the tire forward at different speeds and with different loads. This approach allowed them to look directly at the interaction between the wheel and pavement structure. Many past PVI studies relied on actual trucks on actual pavement and ignored structure and material properties.
“Most of the world is looking from the tires up to understand how to produce less greenhouse gas,” Tom Pyle, pavement management engineer with Caltrans, told ENR. “But we’re looking from the tires down, to the pavement, to achieve efficiencies the public never sees by significantly reducing greenhouse gases.”
Continue reading at MIT News.
Roadway image via Shutterstock.