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How potholes are formed and fixed in Philly

Philadelphians’ soured relationship with potholes runs deep, but the season for bumpy roads is back.

A pothole at 15th and Sansom Streets.
A pothole at 15th and Sansom Streets.Read moreCHARLES FOX / Staff Photographer

Philadelphians’ soured relationship with potholes runs deep, but the season for bumpy roads is back.

Spring means the beginning of the end for freeze-and-thaw cycles that can lead to treacherous terrain for motorists, cyclists, and pedestrians. And it’s time for pothole repairs to get into full swing.

So far in 2019, the Philadelphia Streets Department has filled about half as many potholes as the same period last year, said chief highway engineer Steve Lorenz.

“A lot of that has to do with focusing on good road repair and putting the city back into a state of good repair," especially through resurfacing, Lorenz said of the need to fill fewer potholes.

A handful of readers have raised questions about potholes through Curious Philly, The Inquirer’s forum in which readers submit questions about their communities and our journalists find answers, and on social media.

PennDot spokesperson Chelsea Lacey-Mabe explained that Pennsylvania’s freeze-thaw and precipitation cycles can make the area’s roads susceptible to potholes: “When it’s above freezing and it rains and then the moisture seeps into the cracks in the road and then it freezes, that expands the road and then when a car drives over that, it breaks up the gravel and that’s how potholes are formed.”

Pothole Formation

Cracks form in the road surface. They are caused

by rain, temperature changes, traffic, drainage systems, and age.

Water seeps into cracks.

In freezing weather,

water expands and begins dislodging gravel

and road material.

Road erosion worsens

with each freeze/thaw cycle. Eventually,

the surface crumbles under the weight of traffic.

Cracks form in the road surface. They are caused

by rain, temperature changes, traffic, drainage systems, and age.

Water seeps into cracks.

In freezing weather,

water expands and begins dislodging gravel

and road material.

Road erosion worsens

with each freeze/thaw cycle. Eventually,

the surface crumbles under the weight of traffic.

Staff Graphic

Here’s more on what’s happening this season — from how many potholes have already been filled, to what’s looking to be repaved.

What’s happening this year

From Jan. 1 through about the middle of March, the Streets Department has filled about 17,000 potholes, compared with about 35,000 over the same time last year, Lorenz said.

PennDot, meanwhile, has broken its monthly record for reports to its customer care center. In March, it’s had 2,908 reports throughout Southeastern Pennsylvania, including state-maintained highways in Philadelphia, with about 75 percent of those pothole-related. PennDot has used 3,000 tons of asphalt so far for patching in the region, while it used 18,000 tons throughout last year.

“So, it’s not one of the worst, but it’s definitely an active pothole season,” Lacey-Mabe said.

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This week, PennDot dispatched crews to repair potholes on more than 100 highways, including I-95, I-76, and Roosevelt Boulevard.

“We may not be done with the potholes, either," Lacey-Mabe said. "More will probably creep up and we’ll be patching, at least until mid-June, I would say, just to make sure that we’ve gotten everything.”

Lorenz said the Streets Departments’ pothole numbers might have less to do with weather than with steps taken last year to improve road conditions, including repaving efforts and laying new asphalt on sections of some problem streets until they can be fully resurfaced.

In his recently proposed budget, Mayor Jim Kenney looks to invest $200 million in a six-year program to boost repaving to 131 miles of streets annually.

Five years ago, the department was paving 35 to 40 miles of street a year, Lorenz said. That’s increased to 80 to 85 miles last year, with plans to tackle 95 to 100 miles in 2019.

There’s a lot of factors at play when considering where to resurface, including conditions, development, and utility work.

“We just don’t wake up today to say tomorrow, we’re going to pave this street," Lorenz said.

For example, contracted work along Pine and Spruce Streets is planned for this spring, while work on 15th Street from Chestnut to South Streets and sections of 17th Street is expected later this paving season, Lorenz said.

How potholes are filled

On a given day, there could be six to 10 city crews of three to four people filling potholes, among other responsibilities.

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That hole in the ground could also be considered a cave-in or ditch, and could require more work from a utility company and may need longer to repair than the target of three or four days.

To complicate matters, some potholes could be the responsibility of another entity like PennDot or SEPTA.

“I can understand it from the public’s perception — if they hit a pothole, or they hit a ditch or a street defect, they don’t care whose responsibility it is, they just want it fixed," Lorenz said.

How to report a pothole

Report a pothole in Philadelphia to Philly311 by dialing 311, 215-686-5560, or filling out a form online. Contact PennDot about state roads by calling 1-800-FIX-ROAD or online through the department’s customer care center.