Preventing the pothole problem
Potholes are nothing new for the Northland, primarily due to the harsh winters and freeze-thaw cycles. With temperatures warmer than normal for much of this winter, there have been more potholes than usual.
UMD Civil Engineering Associate Professor Manik Barman, Ph.D., studies pavement materials, design, maintenance, and rehabilitation.
“In the warmer temperatures, snow melts into the pavement, and at night or any time when the temperature is below the freezing point, it becomes ice,” explained Barman. “So when it becomes ice, it pushes the materials out and then it can disintegrate the pavement. Then vehicles go over the weak pavement, creating a crater or depression or pothole in the pavement.”
Related: Meteorologist Brandon Weatherz explains how potholes form
Potholes can be repaired in the winter, but with difficulties.
“There is a cold mix that can be applied on them, but those are very temporary. Another problem is even if you want to patch it with a cold mix, you need to put it on a dry surface,” said Barman. “Now look at today’s weather, the potholes are there. They’re wet. Water is there, standing water is there. Now when you have standing water, even with a cold mix, it just doesn’t work.”
Part of the issue is poor drainage from the way the roads are sloped.
“You can see when you drive like that a lot of the tracks on the centerline of the pavement, the centerline where like two yellow lines, you can see there is a weak spot where when we make the pavement, we cannot compact that area properly. So that remains less compacted and then, water enters through those cracks more,” explained Barman.
Much of this spring will be spent dodging potholes, but more could be done in the future to avoid having so many.
“We really should be blending a good amount of investment on preventive maintenance,” said Barman. “We should be focusing on different preventive maintenance we should do rather than fixing potholes. I think accepting that the climate is harsh with freeze-thaw cycles, planning on more aggressive preventive maintenance, would be a good strategy.”
Adjusting the way roads are built is needed to prevent this issue long-term.
“My research actually leads to creating better roads. Changing the materials, extending existing materials, introducing new ingredients in the materials,” said Barman. “So how can we make materials more resilient, more resilient towards more resilient against harsh climate?“