Motorists who've felt the bumps and jolts while driving down Minot's city streets know the potholes are especially bad this year.
"We are fighting them," street superintendent Rick Hair said. "I have pothole trucks out every day."
Because permanent repairs require warmer temperatures, the city has been making temporary fixes, some of which turn out to be very temporary.
"It will stay really good through three-quarters of the day until things start to melt and you get water in it. Then it's going to get pounded out. It doesn't stay in. That's the issue," Hair said.
Dan Jonasson, Minot public works director, said the city has repaired numerous potholes multiple times already this spring. One of the worst areas is West Burdick Expressway near Sixth Street Southwest, where crews have patched about a dozen times this spring, he said.
To keep up with repairs, the city orders more cold mix from its Bismarck supplier about every week and half. The city now is working through its third load order. Last year, three loads lasted the city all spring. A load typically is close to 30 tons and costs about $5,000, Hair said.
Asphalt plants that make the more permanent hot mix generally open sometime in May. Hair expects to be making temporary repairs through much of May until the plants get ramped up.
Because moisture is the culprit behind potholes, wet years tend to produce more of them, Jonasson said.
Potholes occur when snow and ice melt and water then seeps through cracks in the pavement. The moisture freezes when temperatures drop, causing the ground to expand and push the pavement up. As temperatures rise, the ground returns to normal, but the pavement often remains raised. This creates a gap between the pavement and the ground below it. When vehicles drive over this cavity, the pavement can crack and fall into the hollow space, creating a pothole.
Hair said Minot's problem is aggravated by aging streets. Many streets were paved at the same time years ago, and now as they show deterioration, it creates opportunities for moisture to seep in and freeze.
City crews have been monitoring the street situation, but people also can report pothole problem areas to the Public Works Department at 857-4140. Reported potholes will be put on the list of sites to be patched.