By BRIAN WALKER
Barb Wilson has those dreaded, damaging potholes etched in her mind every morning on her way to work.
"You get used to them, know where they are and learn the best way to avoid them," the Post Falls woman said while filling her car up with gas last week. "But that doesn't make them any more fun to navigate."
Wilson said she dodges potholes every work day on the Interstate 90 onramp at the Highway 41 interchange in Post Falls.
"Luckily, they're avoidable," she said. "I know it's all about timing and the weather, but it will be nice when they are gone forever."
Or at least until next spring, when potholes crop up again as sure as dandelions.
Potholes are caused by winter's freeze-thaw cycles, which create soft spots in roads. Water also enters cracks in the road, causing the base to deteriorate.
"Freezing effects cause the road to expand," said Tim Martin, Coeur d'Alene street superintendent. "When the roads thaw out, they are vulnerable to the expansion and that's when potholes form."
Alan Soderling, Hayden's public works director, said the long freeze and large amount of moisture in February caused the pothole problem in that city to be worse than most previous years.
"The older and more deteriorated roads are typically the ones we see the most problem because of the existing cracks," Soderling said.
Martin added: "The long February cold spell was our major culprit."
A winter weather condition that helped limit the damage, however, is that the precipitation was primarily snow, said Megan Sausser, Idaho Transportation Department spokeswoman.
"Snow by itself can insulate the ground," she said.
Martin said Coeur d'Alene has received more than 50 reports of potholes from citizens. Among the worst roads are Atlas Road, Honeysuckle Avenue and 15th Street.
"The citizens of Coeur d'Alene are very good at letting us know," Martin said.
Martin said this spring has been somewhat unusual in that four "frost heaves" have been found.
"This is caused when the frost is driven much deeper in the roads and then becomes saturated during the thaw," he said, adding that frost heaves are larger than potholes.
Martin said frost heaves have been found on Newbrook off Atlas, Spokane between 7th and 9th, Lunceford off Honeysuckle and at the bottom of Fernan Hill off Pennsylvania.
Martin said Coeur d'Alene spends more than $1.5 million annually on overall street maintenance, including pothole repairs.
Sausser said about $50,000 is in ITD's budget this year to specifically address potholes in North Idaho.
Ken Peterson, Post Falls' streets supervisor, said one of the worst stretches in that city is Seltice Way east of Highway 41 due to the amount of traffic on the road.
Road officials said their agencies don't typically send out workers to specifically search for potholes, but staff continuously monitors them and reports problem areas as they’re found.
Martin said that during cold and wet months, the only option on filling potholes is a petroleum-based asphalt mix, referred to as a "cold mix." It is considered a temporary fix.
"It is pliable and quick to use," Martin said. "It is also the least effective method, but your only option at the time."
Consistent dry weather in late spring opens a more permanent solution that is applied as a hot emulsion, sealing out the moisture better during the rainy season. Hot mix asphalt is generally available in early May and is applied after compromised asphalt has been cut out.
Whether agencies use cold or hot mix depends on the severity and urgency of the problem.
Sausser said ITD used to rely heavily on asphalt overlays to tend to pothole sections, but that wasn't the best option, as adding another layer of asphalt can affect the road's drainage. Overlays are also more susceptible to damage from plows because the surface is not even.
"A few years ago, ITD committed to doing as many milling-and-inlay projects as possible to avoid creating an uneven surface and dealing with the resulting issues," Sausser said.
Milling involves grinding down into the upper layer of the existing asphalt to remove cracks, ruts and imperfections. Then, a layer of inlay paving is placed on top of the milled surface to fill holes and level it off.
However, on non-commerce routes that are typically not eligible for major maintenance projects, an overlay may be performed to keep the cost down, Sausser said.
As roadways wear down after about 20 years, ITD rebuilds roads completely.
Sausser said ITD imposes spring load limits on Highway 53 and Highway 41 from Rathdrum to Oldtown to maximize the life of those stretches and limit damage.
"We typically establish them based on observations from maintenance personnel and sensors in the ground," she said.
The restrictions require trucks at 10,000 gross vehicle weight to be under 14,000 pounds per axle and to travel no faster than 30 mph.
Sausser said potholes can fill with water, so drivers may not know how deep they really are. They can cause vehicle damage or even crashes.
"Avoid driving over them if possible," she said.
Road officials said citizens are encouraged to report potholes to the corresponding jurisdictions.
"Be patient because we are working on fixing them," Soderling said. "Slow down if you cannot avoid them."