Before the snow finally arrived, drivers may have noticed strange lines on the Copper River Highway.
The evenly spaced parallel marks were being made by a state Department of Transportation truck using a salt-brine mixture to eliminate ice on the roads.
“The DOT has been experimenting with the use of salt brine for several years,” said Rob Mattson, Cordova Airport manager. “They have discovered it is much more effective than sand.”
“We have a lot of issues with black ice here in Cordova,” Mattson added. “It is hard to see, and we have discovered this treatment knocks it down in a hurry.”
A DOT video called Anti-Icing 101 describes the methods of applications and benefits.
Basically, salt is added to water to create a 23% salt mix, with another component added to inhibit corrosion.
The solution is then placed on the road surface by a unique application system that releases the brine in even rows at a rate of 0.06 gallons per foot. This is what creates the parallel lines visible on the highway.
The anti-icing solution, which has a freezing point of minus 6 degrees, is typically used on roads at 15 degree or above, and not only impacts black ice immediately, but also softens up snow and ice pack for removal.
The method has been used in northern states for many years and has proved to be far more effective and efficient than sand alone. Typically, one application of brine lasts two to three days, whereas sand may have to be applied two or three times per shift. The result is much more coverage per mile, at much lower cost.
One concern about the use of salt is possible vehicle corrosion. In response to the use of salt brine, vehicle manufacturers have been using more galvanized parts that are much more rust resistant.
The salt brine is also less harmful to the environment and far cheaper than sand to cleanup in the spring, as accumulation of the latter clogs drainage and sewer system.
Cordovans who have seen clouds of dust in the air every spring as the city street sweeper gathers up all the sand dumped on the roads throughout the winter can easily relate to that.
DOT also noted that concerns about wildlife attracted to the salt brine on the road are unfounded, with no more animals near the roads than when salt was being added to sand in prior treatment methods.
So, the next time you see those strange lines on the highway, know it means the crew at the Mile 13 Airport/ DOT station is using the latest technology to make the highways as safe as possible for all of us.