Temperatures flirting with the freezing mark had many winter-weary Minnesotans cheering on Friday, but Minnesota Department of Transportation officials were cringing.

The one-day break from the subzero weather will only exacerbate the pothole problem that’s making Twin Cities roads look like they have a bad case of acne.

Among the worst is Interstate 394 between downtown Minneapolis and Hwy. 100. As one commuter tweeted: “On 394 west between downtown and 100 is like driving on the moon, so many potholes.”

Cliff Gergen, who works in MnDOT’s Smooth Roads maintenance program, says the potholes will be filled as soon as the weather cooperates.

“Snow and ice have been continuing and that is our problem. There is no chance to patch day after day,” Gergen said.

Even if crews had time, he said, “We have to use a cold mix, and our plows would plow it right off. We are aware of what’s going on. A fix is coming, but that doesn’t help the problem.”

I-394 east of Hwy. 100 is particularly vulnerable to the depressions because a thin asphalt overlay is peeling away. Originally built as a concrete freeway, it drew noise complaints from adjoining Minneapolis neighborhoods. The Legislature passed a law in the 1990s directing MnDOT to put down an asphalt mixture with a higher friction resistance to reduce tire noise, said Curt Turgeon, a state pavement engineer.

The first layer was put down in 1996. When that wore out in 2004, MnDOT replaced it with a material that was “stickier and gooier,” which allowed the agency to put on a thinner layer, Turgeon said.

“We were thinking it might stick and perform a little better,” he said.

But now the layer, which is scheduled to be replaced in 2015, is peeling away and concrete joints below are showing through.

Repeated snowfalls have supplied ample moisture to settle in the cracks and freeze, causing the pavement to pop when it thaws.

“It’s like packing ice inside of ice in these crevices,” Turgeon said. “It bores into weak places.”

I-394 is not the only road with pothole problems.

“It’s a statewide problem,” Gergen said. “It never quiets down. It’s always constant.”

Motorists can report potholes at tinyurl.com/oya7dl.


Follow news about traffic and commuting at The Drive on startribune.com. Got traffic or transportation questions, or story ideas? E-mail drive@startribune.com, tweet @stribdrive or call Tim Harlow at 612-673-7768.