Pavement design and fuel economy

While vehicle and engine builders, along with government officials, are concerned with fuel economy and emissions, so, too, are those involved in infrastructure.

Take researches at the Massachusetts Institute of Technology (MIT), by way of example. They are looking at ways to boost fuel efficiency and cut greenhouse gas emissions by building better roads.

Researchers at the school’s  Concrete Sustainability Hub found that how the road is constructed could have a significant impact on the fuel economy of cars and trucks, and less fuel means fewer emissions.

Research models predict the use of stiffer pavements could reduce fuel use by as much as three percent, creating reduction of 46.5 million tons of CO2 each year.


Roughness matters

There has been the understanding that roughness matters more than deflection when it comes to fuel usage, but research has shown that it depends on the road design.

Roughness generally accounts for more fuel use, but researchers found that deflection still wastes 180 million gallons each year on the nation's Interstate System. By comparison, roughness accounts for about 555 million gallons of fuel waste.

Because interstates make up only about 2 percent of the nation's roads, they represent just a fraction of the total picture.

By switching to stiffer pavements, highway authorities could boost vehicle fuel economy  by several percent, MIT says. Concrete is naturally more rigid than asphalt, but that doesn't necessarily mean that all highways need be paved with concrete.

MIT has developed a model to help engineers optimize pavement designs.