WEST LEBANON — Public works leaders throughout the Upper Valley are reporting paved roads are rougher in many spots than in years past.
Conditions this winter produced a bumper crop of frost heaves.
“It’s been really, really bad,” Enfield Department of Public Works Director Jim Taylor said in a phone interview this week. “We always get some frost heaves, but for some season this year seems to have really, really taken a toll.”
The frost heaves primarily have affected paved roads, Taylor said. The town’s dirt roads are in better shape. Usually it’s the reverse during Mud Season, Northern New England’s unofficial fifth season.
“We’ve had good luck with our dirt roads this year,” Taylor said.
This year’s weather conditions play a role, said Jennifer Lane, a New Hampshire Department of Transportation spokesperson. She pointed to heavy rain that hit the region earlier this winter that was then followed by “a stretch of very cold temperatures.”
“That combination allows water to soak into the ground and then freeze, expanding and pushing the pavement upward,” Lane wrote in an email. “When temperatures fluctuate, that cycle repeats, which can make the heaves more severe and show up in places we haven’t typically seen them before.”
Dirt roads are not impacted as much as paved surfaces, which trap water, said Hanover Director of Public Works Peter Kulbacki, who has worked on New Hampshire roads for around 40 years.
In addition to the freeze and thaw cycles, other factors come into play, Kulbacki said. Roads that are built on silt and clay are more susceptible to frost heaves because water doesn’t drain as well as it does in sandier soil.
Additionally, frost heaves tend to form on flat stretches where water is more likely to pool and freeze, versus hills which water will drain down, Kulbacki said.
“It’s in spots. It’s not everywhere,” Kulbacki said about where frost heaves form on roads.
Kulbacki said public works staff are keeping an eye on numerous roads, including South Park Street in downtown Hanover.
“We’re seeing a lot more frost heaves than we’ve ever seen,” Kulbacki said.
South Park is relatively flat and the frost heaves are the worst near the shoulder on the west side of the road because it is built over soil that has more clay and silt in it.
Enfield’s Taylor also has noticed problems with particular roads, including George Hill Road off Route 4A, which crews recently paved. The road was built on soil that doesn’t drain as well. It also has flat sections where the frost heaves are the worst.
“It’s like we were never there,” Taylor said. “We’re hoping it comes back into shape. If it doesn’t, it’s going to be an expensive project for next season.”
Employees will assess the roads over the next couple months, as warmer temperatures take root and below-freezing nights go away until fall. Depending on the road, it can cost $60,000 to $80,000 per mile to repave a road, Taylor said.
“There’s not much you can do this time of year,” Taylor said.
Thetford Department of Public Works foreman Dale Lewis said he started noticing more frost heaves on the town’s paved roads about six weeks ago.
“They kept getting worse and worse,” Lewis said in a phone interview.
Now he’s hopeful that the worst of the frost heaves are over.
“They seem to be going back down,” he said.
Crews have been patching holes when they can, though more work will take place once it gets warmer.
Not all towns have seen worse conditions than usual. Hartford highway foreman Michael Kollman said the roads there are about the same as any March.
“I think for us it’s been a normal year,” he said in a phone interview.
Crews have turned their attention to filling potholes and this week hit spots on Old Quechee Road and Quechee Main Street.
“We try to keep up with them,” Kollman said, as weather allows.
Hanover public works staff plan to start an assessment of the town’s roads next week and will adjust summer road projects based on what they learn, Kulbacki said. They did an assessment last fall, but after this year’s frost heaves they’re taking another look.
There’s not much motorists can do to avoid the bumps.
“Slow down. That’s the best thing you can do,” Kulbacki said. “That frost heave today can be a pothole tomorrow.”