NewsOperation Safe Roads


ADOT and MAG considering what to cover the freeways with in the future

Gabrielle Waddick Phoenix Freeways
Posted at 6:57 PM, May 19, 2022
and last updated 2022-05-20 17:34:14-04

PHOENIX — Much of the pavement on Phoenix freeways is old and breaking down and there's a hot debate right now on the path to smooth sailing again.

Drivers like Jeff Wycoff, with L&W Supply, spend every day traversing the Phoenix area freeways, and spoke to ABC15 when ADOT opened public comment for its five year restoration plan earlier this month.

"Hitting all of the potholes on the 17 in the morning, I'm like... 'When are they going to fix this?'" Wycoff said.

ADOT along with the Maricopa Association of Governments is diligently working on a plan, but the dilemma they're facing now is what type of surface is best to line the freeways with.

Back in the late 1990s and early 2000s, a rubberized asphalt was chosen as part of then Governor Jane Hull's "Quiet Pavement Pilot Program."

The goal was to reduce noise pollution and meet federal highway safety standards.

This was back when the Phoenix freeway system was expanding to meet the needs of a growing population.

Freeways were funded as part of Proposition 300 and came online with the Loop 101 and 202.

"Where there were no freeways before, you had freeways all of a sudden, and with that came noise," said John Bullen, Transportation Economic and Finance Program Manager for Maricopa Association Governments.

The rubberized pavement asphalt appeared to work early on.

"So what they found was that initially, rubberized asphalt provides a pretty significant noise reduction, however over time that noise reduction diminishes," Bullen said.

"The Federal Highway Administration determined that you could not use the rubberized asphalt for sound mitigation," he added.

And Bullen says after about 10 years the rubber surface begins to break down.

"That's really where we start to see the cracking and the potholing," he said.

Leading us to now, with ADOT and MAG now testing a new covering method called Diamond Grind.

"They saw in grooves, if you will, into the concrete itself," Bullen said.

Agencies are still taking noise into account.

"Supplemental noise reduction is a very important thing to have for our residents and for the community," Bullen said.

And while Diamond Grind does reduce noise, he said its main benefit is cost, cheaper than rubber by a mile.

"ADOT just completed a study and what they found was between now and 2050, there's about a $1.5 billion cost difference," he said.

ADOT is already testing the Diamond Grind on certain sections like the 101 Price Freeway.

Bullen says more testing needs to be done before a final decision on a surface is decided.

MAG has already earmarked $750 million for the total freeway restoration, the bulk of the money coming from a hopeful renewal of the half-cent sales tax.

Drivers like Wycoff say they'll consider voting for it, but they're going to need some assurances first.

"As long as we see stuff getting done, I think that's going to be what really makes it OK," Wycoff said.

As for a timeline...

"We hope to bring that to the voters in November as part of a larger package, but first we need authorization from the state legislature," Bullen said.