Engineers and scientists in several states are attempting to pave the way to a quieter future, try out rubber, asphalt and gravel looking for a way to make roadways less loud.
Virginia is testing a number of stretches of speculative pavement as part of a $7.5 million state job. Arizona and California have actually been trying different highway surfaces meant to decrease sound. Washington state, which has sampled numerous surface areas with limited success, is pressing ahead with others.
Far, efforts in the field of so-called peaceful pavement are revealing combined outcomes. Some surfaces can be more expensive to put down than conventional streets and have the tendency to require more regular repair works, according to pavement engineers. Other experimental surfaces have broken down with time and ultimately end up being even noisier than the initial pavement they changed.
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As part of the Quiet Pavement Pilot Program, an asphalt and rubber overlay was used to part of the 101 highway near Phoenix, decreasing noise in one comparison from 79 decibels to 70 decibels. Listen to recordings made along the highway in areas that did and did not have the overlay.
The inspiration making roadways quieter is great. The noise of freeway traffic about 50 to 100 feet away– a common distance between highways and homes– usually runs 65 to 75 decibels, about the volume of a regular discussion heard 3 feet away, stated Paul Donavan, a senior scientist at Illingworth & Rodkin Inc., a company focusing on acoustics and air quality.
Trucks have to do with 10 decibels louder than vehicles, said Dr. Donavan, who has a doctorate in acoustics from Massachusetts Institute of Technology. A boost of 10 decibels represents a doubling in loudness to the human ear.