The Idaho Transportation Department hopes magnesium chloride is the answer to motorists’ winter woes.
The department has been spraying a concentrated brine of the salt on the highway between Lewiston and Orofino this winter.
“We’ve been having very good success with it,” said Pat Lightfield, district maintenance engineer.
The brine lowers the freezing point, preventing frost and ice from forming. Lightfield said crews have sprayed the brine on the highway twice a week.
The district has targeted the stretch of Highway 12 between Lewiston and Orofino to test the brine because it runs along the Clearwater River and frost often forms overnight.
Crews also are trying to spray the road before snowfalls to prevent the snow from freezing to the pavement, allowing the department to clear the road more easily.
The highway also appears wet or icy after the brine is sprayed on. It may be free of ice, but motorists should use more caution where the brine is sprayed than wet pavement might prompt, Lightfield said.
“It’s not like wet pavement or dry pavement. It still has a little slippery to it,” he said.
The agency tracked weather conditions, temperature and the concentration of magnesium chloride in the brine in an effort to be as scientific as possible.
“The more scientific we’ve become, the better success we’re having,” Lightfield said.
The district has been experimenting with the brine for 10 years. The department has also used it in Boise, Sandpoint and Coeur d’Alene, where air quality regulations limit the use of sand or gravel because of the dust they produce.