The warm weather will be great – until the potholes show up

When temperatures rise above 40 degrees today, and past 50 degrees Friday, it'll be great to shed our hats and gloves and drive with our car windows open a crack.

What won't be so great is what happens Saturday: Temperatures will fall back into the 20s, and potholes will start forming beneath the streets.

The freeze-thaw cycle that's common in Chicago winters wreaks havoc on the pavement, creating potholes. They form when melted snow and ice gets under the road and then contracts and expands as temperatures rise and fall.

“When the weather gets warm, you're not immediately going to see them pop up all over the place,” explained Adam Boeche, Des Plaines' assistant director of public works and engineering. “A week or two from now is when they're going to show up.”

Guy Tridgell, spokesman for the Illinois Department of Transportation, said this is the first freeze-thaw of the year, and it usually takes a few cycles before any significant pothole problems arise. However, he added that January is historically when “the calls start coming in.”

“The real damage is done by continual cycles of freezing and thawing,” he said.

Suburban highway and public works departments expect these fluctuating temperatures and have pothole patching crews ready to go. But the more often the temperature fluctuates like this, the more potholes pop up — and the more costly it becomes to patch them.

The roads most susceptible to potholes are those that were in poor condition or had cracks in the pavement before winter hit, or were damaged by snow plows, local highway department officials say.

Tridgell predicts this year's potholes won't be as bad as in previous years, because IDOT has done so many road reconstruction projects.

“Anyone who's driven on the roads the last few years knows there's been a lot of roadwork that's been going on. While it has been an inconvenience, one of the benefits that you do see is fewer potholes in the winter and spring,” Tridgell said.

While good road maintenance helps quell the problem, no road is immune, said Christopher Snyder, DuPage County's chief highway engineer of design and construction.

“We try to fix poor pavement sections before winter ... because it's a lot easier to patch in warmer weather than it is cold,” Snyder said. “We do what we can. If you get enough traffic going over those soft spots, the pavement will eventually fail.”

To report a pothole on a state road, call the Illinois Department of Transportation at (800) 452-4368 or your local public works department.