The weather has not been kind to our streets this year.

A lot of snow fell and stuck around. Warm weather came around. The snow melted and froze, melted and froze, melted and froze. The melting water found its ways into all the nooks and crannies in our streets. Standing water weakened the wet pavement. And then the pavement froze again. And again. CRACK! BOOM! CRASH! As if overnight, potholes erupted all over the city.

It was the perfect storm for a pothole bonanza.

The City has been attempting to keep up with the pothole repairs, but the cold temperatures, rain, and snow have made it difficult to patch any pothole more than temporarily.  

After this weekend’s snow storm, the standing water and melting snow on the streets has potentially made the situation much worse.

“Water is the enemy of the pavement,” Manik Barman, an associate professor at the University of Minnesota-Duluth who studies infrastructure and pavement engineering, told me over the phone on Thursday.  

Days of standing water and melting snow are compounding on top of months of cold, water-soaked pavement that continues to be a challenge to repair.

Before the snow took over the streets Friday night, the City’s Public Works department was patching potholes with hot asphalt using the “throw and go” method. Heaps of hot asphalt filled up potholes and drivers flatted the heaps as they drove over the soft bumps.  

We reached out to Barman, an associate professor at the University of Minnesota-Duluth who studies infrastructure and pavement engineering and the director of the City’s Transportation Maintenance & Repair Department, Joe Paumen.

Your questions

Why do some streets have a lot of potholes and others don’t? For example, 35th and 36th Streets near 35W are full of very big potholes.

There are many variables that can result in a street having a lot of potholes. How old the pavement is, the condition of the pavement, and the weight of the traffic can have all an impact.

“The weight of the vehicle does matter,” the director of the City’s Transportation Maintenance & Repair Department, Joe Paumen, said.

I hypothesized that the potholes were so large on 36th Street due to the heavy construction machinery and consistent vehicle traffic near the 35W ramps.

Paumen said he wasn’t familiar with the area and couldn’t pinpoint a specific reason for the size and severity of the potholes but he did elevate the area for repair and I saw that the potholes were patched the following day. Information on how to report potholes is further into the article

If my car faces damage from potholes, how easy is it to submit a claim to the city and actually get reimbursed for the damage? I'm also interested in knowing how much the city has paid out for pothole damage.

“The claims are often denied,” Paumen said. The City has to be found “negligible” which legally equates to not having a patching program. Given that the Department of Public Works has an active pothole patching program in place, it would be unlikely that the City would be found negligible. Paumen didn’t have exact numbers in front of him but made it clear people are rarely awarded money for pothole damage claims.

In Minnesota, potholes are a “fact of life,” as Paumen put it. This means drivers should continue to drive carefully and cautiously throughout pothole season.

Roads that have recently been repaved, within the past 2 years, have zero potholes. Maybe it’s time to apply some pressure on the city and state to start repaving roads more often than every 34+ years! As I understand it, the current roads are designed to last 20 years.

Yes, Barman confirmed the city pavement is currently designed to last 15-20 years. In our conversation, he also touched on pavement longevity and climate change. When pavement is designed, factors are considered, such as the amount of traffic on the road, weather patterns, and soil conditions in the area. The “end of design life” also includes the inevitable potholes. Barman encouraged people to push their legislators to include climate change factors (e.g. thaw-freeze cycles, extreme heat) into new pavement design.

Barman also mentioned that freeway pavement is designed differently from city street pavement. Drivers typically encounter fewer potholes on freeway pavement because that pavement is designed to withstand pothole conditions.

“It’s not impossible to build pothole-free roads,” Barman said.  

Are the cold patches even worth doing since they create so much debris in the road? Either way I have to avoid something in the road, either the potholes or the debris that covers a wider area than the potholes.

The City officially switched over to hot mix on March 20, but this is a great question. In a press conference about pothole repairs in March, Mayor Jacob Frey said cold mix is a temporary and imperfect solution. “Some of it sticks and some of it doesn’t,” Frey said.

There were more thaw-freeze cycles after cold patches were set which didn’t help any, of course. As the melting snow froze and melted, the running water carried chunks of cold patch out of the potholes and onto the pavement.

A MnDOT study in 2018 reported “More fluid, cold-weather asphalt mixes designed for patching don’t always compact properly or adhere well to pothole walls.”

So, reader, you were onto sometime. Cold patch isn’t the greatest.

Here is the Minnesota Department of Transportation’s Asphalt Patching Methods Best Practices as a flow chart, compiled from Barman’s more extensive research on the subject.

Is the increased use of shorter-lasting mill-and-overlay on city streets contributing to potholes appearing more quickly?

Mill-and-overlay is a typical part of street construction. At the March 15 press conference, Frey said, “We can’t go through the full street reconstruction, or the mill-and-overlay, or fill these potholes on a permanent basis until we know that the freeze-thaw cycle is finished.”

When I spoke with Paumen on the phone, he had a good sense of where each road is at with its life cycle, so the City is aware of how the age of the street leads to more potholes.

Barman argues that more effort needs to go into creating road design that accounts for multiple freeze-thaw cycles and that street cracks need to be repaired as fast as possible.

Preventing potholes

Despite the state of our streets right now, the good news is that potholes are preventable.

Research by Barman and other pothole scholars have found that fixing cracks in pavement when they first form is the best way to keep potholes from forming. It is through these cracks that the enemy of pavement, water, enters.

In other words, cracks in the roads equal future potholes.

“Prevention is better than the cure,” Barman said. Crack filling is roughly a quarter of the cost of patching potholes.

To mitigate potholes, “we work on our roads year round,” Public Works Director Margret Anderson Kelliher said at the March 15 press conference. City mitigation includes crack sealing, street reconstruction, and resurfacing.

“The only way out of pothole season is really those things,” Anderson Kelliher said.  

Beyond street conditions, Barman argues that keeping the streets dry is very important. He stressed the importance of investing in quality drainage systems.

“It’s very important to keep the drainage system clear,” Barman said.

Barman said if there is stagnant water in the road that’s a sign the drainage system is not working. Keeping water out of the roads minimizes potholes so maintaining a clear drainage system is paramount.

“We should be concentrating on this,” Barman said.

Reporting potholes

Paumen stressed that reporting potholes will result in getting the potholes patched. The City knows there are a lot of potholes out there but the Public Works crews don’t know where they all are. What seems to be a major pothole problem to you may not be known to the crews.

Here are a few important things to know about reporting potholes:

  1. Using an address is better than an intersection. The 311 app allows you to move a red X to the exact spot of the pothole.
A screenshot from the 311 app's pothole reporting function
  1. Don’t try to submit a report for multiple blocks. One block of potholes at the most. I tried to submit a report for 1st Avenue and 36th Street and then made comments about Stevens Avenue, too. My report was closed within a few minutes.
A screenshot of the 311 website pothole report form
  1. Paumen says pictures are helpful. You can upload pictures when emailing 311 or using the 311 app.
An example of a picture of a pothole that would be useful for the Public Works crews.
  1. If it is safe to do so, Paumen said crews would appreciate measurements of the potholes. This helps Public Works escalate the biggest potholes to the top of its routes each day.  
An example of a pothole measurement. Photo by Julie Tilsen.

As pothole season continues, residents can continue to help City crews by keeping street drains clear of debris, reporting potholes with as much details as possible, and traveling with care and caution. The sooner the pavement dries out, the sooner the City can fix the potholes using more permanent methods.