Alaska Department of Transportation and Public Facilities employees are out working on a pothole and underlying sinkhole that formed on the Kenai Spur Highway Tuesday night.

“Basically last night a motorist noticed it, and it’s about 2-3 feet across at about mile 12 of the Kenai Spur,” said Shannon McCarthy, public information officer for DOT’s central region.

Lt. Dave Ross with the Kenai Police Department said several calls began coming in at about 5:49 p.m. Tuesday. Kenai Police responded to the area and helped direct traffic away from the hole while DOT took a look, he said.

It is common for potholes to form in the wake of freeze-thaw conditions, and McCarthy said pothole formation has been pretty active in the state’s central region this winter.

“We don’t always know where the potholes are forming,” she said.

The hole on the Kenai Spur Highway formed near a manhole, so members of the department went down it to search for any potential causes for the sinkhole, McCarthy said. So far, nothing is obvious as to a reason for its formation, she said, though since the road is near an old embankment and is about 30 years old, it could have been an issue with organic material in the road that deteriorated over time.

Department employees will dig up the “bad material,” or the broken pavement, and replace it with packed gravel, patching the hole, McCarthy said.

If the sinkhole underneath is a minor problem, which McCarthy said it looks to be as of Wednesday morning, it should be a relatively quick fix.

The road was already scheduled to be repaved this summer.

McCarthy said it is important for motorists to drive slow over the sinkhole, and to always report potholes to DOT at 262-2199 and to law enforcement.

Reach Megan Pacer at megan.pacer@peninsulaclarion.com.