A new MIT study shows that using stiffer pavements on the nation’s roads could reduce vehicle fuel consumption by as much as 3 percent — a savings that could add up to 273 million barrels of crude oil per year, or $15.6 billion at today’s oil prices. This would result in an accompanying annual decrease in CO2 emissions of 46.5 million metric tons.
The study is the first to use mathematical modeling rather than roadway experiments to look at the effect of pavement deflection on vehicle fuel consumption across the entire U.S. road network
The deflection under the tires is similar to that of beach sand underfoot: With each step, the foot tamps down the sand from heel to toe, requiring the pedestrian to expend more energy than when walking on a hard surface. Stiffer pavements would decrease deflection and reduce that a car’s “footprint.”
“This work is literally where the rubber meets the road,” says Professor Franz-Josef Ulm, the George Macomber Professor in MIT’s Department of Civil and Environmental Engineering. “We’ve got to find ways to improve the environmental footprint of our roadway infrastructure.”
The researchers also say the misconception that to go green means spending more money is not necessarily true. And, even if there is an initial cost outlay for better pavements, it quickly pays for itself not just in fuel efficiency and decreased CO2 emissions, but also in reduced maintenance costs.