The ADOT Noise Team works to mitigate noise for federal projects as required by the National Environmental Policy Act (NEPA). Noise guidance documents for projects are located on the Technical Guidance
page under Noise Abatement.
Building a Freeway: Rubberized Asphalt.
UPDATE: ADOT has completed its Quiet pavement program. The Federal Highway Administration has issued an updated memo to clarify its position on use of pavement as a noise abatement measure. The memo reiterates that regulations at 23 CFR 772 do not allow for the use of pavement type or surface texture as a noise abatement measure. FHWA will continue to consider pavements as contribution to the noise abatement measure if evaluated for the pavement's full life cycle. The FHWA will also allow new Quiet Pavement Pilot Projects that evaluate the pavement for its full life cycle, to avoid premature overlay of the pavement solely to restore the noise reduction. FHWA encourages highway agencies to continue researching their pavement types and surface textures and to construct those pavement in accordance with their agency's requirements. The FHWA will continue to investigate data used for its Traffic Noise Model and "average pavement type" for noise analyses on projects.
INFORMATION: Highway Traffic Noise - Guidance on Pavement as a Noise Abatement Measure
Originally published on April 10, 2013
A three-year, $34 million project to surface about 115 miles of Phoenix-area freeways with rubberized asphalt is working toward a smoother ride for motorists and quieter neighborhoods for those who live adjacent to the roads.
The first areas to receive the “quiet pavement” were on the Loop 101 Agua Fria Freeway from Union Hills Drive to 31st Avenue, and on the Loop 101 Pima Freeway from 21st Avenue to Tatum Boulevard and from Frank Lloyd Wright Boulevard to Mountain View Road. State Route 51 was resurfaced from Shea Boulevard to Bell Road. The entire Loop 101 and SR 51 freeways plus sections of Interstate 10, Interstate 17 and the Loop 202 Red Mountain and Santan freeways will also receive new rubberized asphalt surfaces.
What Is Rubberized Asphalt?
Rubberized asphalt has been used for more than 20 years to resurface highways and city streets in Arizona when pavement surfaces reach their normal life expectancy. While it helped reduce the disposal of used tires, it recently has been recognized for its reduction of traffic noise.
Description of Rubberized Asphalt
Rubberized asphalt consists of regular asphalt paving mixed with “crumb rubber" which is ground, used tires that would otherwise be discarded or take up space in landfills. Used tires are processed by separating the casings, fabric and steel. The extracted rubber then is ground to the consistency of ground coffee. Rubberized asphalt has the benefit of being smoother and quieter. Noise readings have shown the rubberized asphalt generally reduces tire noise by an average of 4 decibels.
Approximately 1,500 tires are used for every lane-mile of rubberized paving, which can put a major dent in the 2 million used tires that are generated annually in Maricopa County. Those used tires usually end up in landfills or in storage. Landfill space is at a premium, and tires in storage are a fire threat.
Rubberized Asphalt Is Temperature Sensitive
Rubberized asphalt cannot be applied during cold weather or very hot weather. The concrete pavement surface needs to be between 85 and 145 degrees Fahrenheit for the material to adhere properly. So rubberized asphalt can only be applied in the spring and fall in the Phoenix area, from March 15 to May 31 and from September 1 to November 15. Prior to application, contractors must repair pavement cracks, chips and joints and prepare the concrete surface for the rubberized asphalt overlay.
The Quiet Pavement Program was developed by ADOT in cooperation with the Maricopa Association of Governments (MAG) and area cities. It will be completed over a three-year period and funded using $34 million from other regional projects.