Colder temperatures during the winter months have taken a significant toll on the roads of the city of Champaign.

Eric Hintsa, program director at the National Science Foundation, said pothole formation occurs as a road ages. “Small holes in the asphalt fill with water and freeze causing expansion in the rock. This expansion loosens other rock and can eventually cause a large hole,” Hintsa said.

Potholes may also form as stones breaks loose from the asphalt. As rain fills these holes, pressure from vehicles compressing the rain water loosens surrounding rocks.

“After this has occurred you no longer need rain water or ice to perpetuate the process,” Hinsta said. “The pressure from the vehicles on a large hole will push the asphalt around the edges enough to continue loosening the rock.”

Pat Barnes, a service advisor of O’Brien Toyota in Urbana, said potholes can cause a significant amount of damage to a vehicle depending on how large the pothole is and how fast a vehicle is moving.

“Although potholes can cause a wide variety of damage to a vehicle, including weakening of the tire wall, balance and alignment issues which are the most common,” Barnes said.

Depending upon the angle and speed of the vehicle when it hits a pothole, three results are common. The force may cause the wall of the wheel to bubble and create a weak spot, throw the wheel alignment off, or bend the rim of the tires, which affects the balance of the vehicle, Barnes said.

With the help of Champaign residents, city officials are closely monitoring potholes during the cold winter months.

“We haven’t had a lot of potholes reported yet, said Arnie Morrison, asphalt supervisor of the city of Champaign. “It is just the start of pothole season. The fact that this year the temperatures have started off as cold and stayed cold has probably kept the numbers down.”

According to Champaign’s Web site, the city had patched a total of 15,437 potholes from January to the end of July 2008.

“Although we do try to be proactive and find the potholes on our own, we do have 685 lane miles of street which is a lot to cover,” Morrison said. “Already this year we have patched 1,094 potholes since the first of January 2009.”