Asphalt is a smooth operator
Smooth, flexible pavements constructed from hot mix asphalt stand up to the punishment of heavy trucks and other vehicles, significantly reducing the initial and total costs over the entire life cycle of a road. At the same time, the smoothness of asphalt pavements reduces wear and tear on all vehicles, saving on maintenance costs.Smoothness has an impact on fuel economy. In 2007, Applied Research Associates reviewed a database from Ontario's Ministry of Transportation containing over 35 years' worth of biannual pavement condition surveys. Their report found that asphalt payments are much smoother initially and remain smoother over their lifetime when compared to concrete pavements. According to the US Federal Highway Administration (FHWA), "Roughness as measured by [International Roughness Index] IRI generally has the greatest effect on fuel economy for typical ranges of IRI on U.S. highway networks." 1 Tests from the FHWA's WesTrack, located on the grounds of the Nevada Automotive Test Center (NATC), some 60 km southeast of Reno, measured the relationship between smooth pavements and improved fuel economy. In the WesTrack tests, smoother pavements lead to lower fuel consumption by 4.5 percent. 2 Asphalt pavements start out smooth and stay smooth over the long haul.