Sound wall construction on the Loop 303 project

Sound walls are built to block sound waves and … actually, that’s about all they’re designed to do.

Despite serving pretty much just one single purpose, sound walls are important features in freeway design – especially to those living near a freeway. That’s because, if they’re doing their job right, sound walls very effectively reduce the traffic noise that reaches a nearby residential area.

But, you probably know all this, especially if you read the blog post from over a year ago where we detailed some of the methods ADOT employs to minimize noise impacts and described how sound walls work.

So, why are we blogging about noise again?

It’s because several sound walls are being built in the residential areas along Loop 303 and I-10 and we thought it’d be the perfect time to revisit sound walls and provide some fresh information.

Noise Mitigation and the Loop 303 project
Sound walls are going in on the Loop 303 project where warranted in accordance with scientific noise studies.

You might remember from our previous blog post that ADOT has one of the most progressive noise-reduction policies in the nation. Federal law mandates that DOTs mitigate noise when the decibel level is 67 and higher, but ADOT has taken it a step further and considers 64 decibels to be the acceptable threshold to consider noise abatement for new projects.

Right now six walls are under construction in the Surprise stretch of the project and other walls are slated for areas within the 303/I-10 interchange section.

Residents might have noticed the rebar “cages” that are being constructed along with the wall footing that’s being poured. Concrete footing, by the way, serves as the wall’s foundation and is being poured at a rate of about 400 feet per day.

After the rebar is placed and the footing is poured, crews backfill the footing with dirt, build wall and paint it. The sound walls in this area of the project will be 14-18 feet tall and should be finished by spring 2013.