Cincy Science: Local professors explain the formula for the potholes that plague us

CINCINNATI - Ever ask, "What is that?" Or, "Why is that?" In our new "Cincy Science" feature, we talk with people who can answer those questions: The folks who do science in Cincinnati and the Tri-State.

As if the freezing temperatures and dicey daily commute were not already getting old, here come the potholes.

The recipe for a pothole is simple, but the science behind it is usually overshadowed by the groans the unexpected dips in pavement cause.

“This is the time of year where we get a certain kind of pothole that’s associated with the freezing and thawing cycle,” said Scott Nutter, a professor of physics at Northern Kentucky University. “It takes two ingredients to make potholes of this type. One is weather and the other is traffic. “

This year, Tri-Staters have had enough of both to cause bumpy commutes on formerly smooth streets.

When water freezes, it expands, Nutter explained. This is why icebergs and ice cubes float: ice forms on top of bodies of water and potholes form.

“Because of this snow you get frost heave. That starts making a pothole,” Nutter said. “Water gets in or under the asphalt, until it freezes. It heaves a little bit to cause the asphalt to move up a little bit. When it thaws and shrinks traffic goes over it.”

Voila: the pothole, which is only made worse by the amount of salt cities have used on roadways this season.

WATCH: Pothole Problems

Another factor, when it comes to the road, is what it is actually made of. On concrete, potholes are likely to form around cracks. Asphalt, on the other hand, is prone to rippling.

This rippling can occur anywhere, but Joe Christensen, chair of the department of math and physics at Thomas More College, echoes Nutter.

Higher traffic roads, such as interstates, aren’t as prone to potholes as city or suburban streets.

“I think to some extent residential roads aren’t built to the same strength, because they aren’t expecting as much traffic,” Christensen said. “It’s also true that trucks significantly wear the road more than cars. In places where you are going to have heavy truck (traffic) there’s damage.”

The damage can cause car troubles, too.

“Certainly the impact isn’t good for your car,” Christensen explained. “One thing is that if you have one tire hitting (the pothole) and not the other, it’s not an even impact. You’re twisting one tire and it can twist off the alignment.”

Great. When is spring?


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