Potholes: What's causing them, and the science that could make roads more durable

ByLuz Pena KGO logo

Tuesday, January 17, 2023

Potholes: What's causing them and how to prevent them

If you drive in the Bay Area, chances are you've already been a victim of a pothole. What's causing them and how could we prevent them?

SAN FRANCISCO (KGO) -- If you drive in the Bay Area, chances are you've already been a victim of a pothole.

"Every county is seeing potholes. Right now we have our maintenance crews out making those repairs," said Pedro Quintana, public information officer for Caltrans.

From the air, SKY7 captured crews repairing potholes Monday on northbound lanes of Highway 101 in Redwood City. Up close, the numbers are staggering. In San Francisco, the public works department reports an average of 600 potholes a month. They've already surpassed that number in the first 13 days of Jan. Our highways are also saturated with potholes.

MORE: 391 reports of potholes across Bay Area in last 12 days, Caltrans says

"In 2022 for the entire month of January, we had about 380 reported potholes across the region. Starting from this month January 1, 2023 to until now, we have seen over 400 reported potholes throughout out highways," said Quintana.

What's causing them? Turn out the rain is only aggravating the damage that was already there.

"We are playing catch-up right now and we just got this big rainfall, so a lot of those pavements that got cracked when we didn't have enough money, are now the water is getting in and pieces are popping out," said John Harvey.

MORE: 'Pothole Vigilantes' come out at night to fix Oakland streets

UC Davis professor John Harvey is the Director of the UC Pavement Research Center. In the lab, his team is testing a mixture of materials to help our roads last longer.

"We are looking at higher recycled content using old asphalt pavement in new asphalt pavement, but with something called rejuvenators. We are looking at concrete that has less cement in it," said professor Harvey and added, "Using tire rubber in the surface. Recycle tire rubber helps us get overlays of asphalt that would last longer. They can ride out over the cracks better and handle that movement over the cracks. There are also polymers that are included in asphalt. Starting to look a little bit at recycled roofing shingles and in the future, further out in the future starting to look at pine tree-based resins and oils to bring into the pavement to help soften and recycle."

Professor Harvey says more needs to be done to maintain roads, not just react when potholes happen.

"Those cracks there. The damage was done over years of under investment," said Professor Harvey.