How Can Asphalt Reduce Noise Pollution?
Many studies over the years have shown that HMA pavements reduce the sound produced at the tire-pavement interface. Special surfacings such as open-graded friction course (OGFC), stone matrix asphalt (SMA), and gap graded blends provide excellent skid resistance while reducing highway noise. When the concrete Superstition Freeway in the Phoenix area was overlaid with open-graded mixture, the reduction in noise was so dramatic that residents of other areas began demanding to have the concrete freeways through their neighborhoods get the same treatment. Arizona’s state and local governments soon responded with a $34 million resurfacing plan that will encompass 115 miles of existing concrete freeways in Maricopa County, which surrounds Phoenix, the state capital. Several European countries are using HMA as a means to mitigate noise issues on their roadways at the source.
