LA GRANDE — From a distance, the tall three-sided shed in eastern La Grande almost appears to house a small mountain of faceless snow, which is ironic. It actually is filled with what some call “highway heat.”

The structure is one of the Oregon Department of Transportation’s rock salt sheds, which are again serving the agency as it begins its sixth winter of using rock salt to reduce ice on interstates in Northeastern Oregon.

Statistics are not available to indicate how the salt is affecting crashes, but anecdotal information about the effectiveness of its use is promising.

“We have a lot less closures now due to ice and snow on the road,” ODOT spokesperson Tom Strandberg said, adding Interstate 84 still has many closures in winter due to high winds and truckers getting into accidents because they did not use chains.

Ken Patterson, manager of ODOT’s Region 5, which includes all of Eastern Oregon, agrees that salt is making a positive impact.

“Salt has been a good tool for us,” he said. “Roads are now open more frequently because of it.”

Patterson noted that after snowstorms, ODOT crews clear interstates faster than they did before, mainly because salt prevents ice from forming under the snow. When crews push away snow with plows after a storm, the road under it is often instantly clear of snow and ice.

“They can move snow more quickly than before,” Patterson said of the ODOT crews.

‘A good deal for us’

ODOT received permission to begin using rock salt in Northeastern Oregon after a pilot project on two roadways in Southeastern and Southern Oregon were successful — the 120-mile stretch of U.S. Highway 95 in the southeastern corner of Oregon between the Nevada and Idaho borders and an 11-mile section of Interstate 5 over Siskiyou Pass at the southern end of the state.

During the pilot projects, the number of crashes in the Interstate 5 test area dropped 27%, and the number on Highway 95 fell 23%, according to statistics the department published in the pamphlet “ODOT’s Use of Solid Salt.”

In addition to the positives salt offers, it is proving to be a dollar stretcher. Patterson said the use of salt means ODOT has to use less sanding rock on roadways, which ultimately costs more to use than salt.

“It is a good deal for us,” he said.

Salt is less expensive to use than sanding rock because ODOT crews must pick up the sand after it is put down, a process that is costly, Standberg said.

The state road department uses about 200 pounds of rock salt per mile per lane for each application. The amount varies depending upon weather conditions. Sometimes as little as 100 pounds per mile is applied, said Robin Berheim, interim manager of ODOT’s District 13.

Salting icy roads lowers the freezing point of the water that forms ice, which leads to melting and prevents falling snow or rain from freezing. The magnesium chloride ODOT has long used lowers the freezing level of water but not to the degree salt does.

ODOT advises drivers to wash their vehicles after traveling on the interstate in the winter, to prevent the effects of salt, which is significantly more corrosive than magnesium chloride.

Some people were initially concerned about the impact rock salt would have on their vehicles, but Strandberg said he has not heard complaints in the region about vehicle damage caused by the use of salt in the winter.

Patterson said the goal of crews is to be as efficient as possible in the use of salt so that no more than necessary is used to get the maximum effect. Crews are developing an understanding of how much salt is needed in specific situations as they gain more experience.

“It is an art,” he said.

A valuable tool

Berheim said salt is not used when the temperature drops well below freezing because it begins losing its effectiveness at this point.

“Salt does not work as well when the temperature drops under 20 degrees,” she said.

One reason, Berheim said, is that when it becomes colder, conditions become drier, preventing salt from getting the moisture it needs to start the dissolving and melting process.

Berheim also said rock salt works better when there are many motor vehicles coming through, putting pressure on it.

“Traffic helps get it activated,” she said, explaining that traffic works salt into the snow and ice.

Sites where there are ODOT salt sheds in Northeastern Oregon in addition to La Grande include Ladd Canyon, Meacham, Baker City, Pendleton, Hermiston and Irrigon.

Berheim said salt is very valuable but that its importance should be kept in the proper perspective and that it is used with options like sanding rock and magnesium chloride to keep snow and ice off roads.

“It is another tool in the tool box,” she said. “It is not a miracle cure.”

Strandberg voiced a similar sentiment, stressing that driving at speeds that are right for the conditions is the ultimate key to traveling safely in Eastern Oregon during the winter.

“Drive slowly and adjust according to the conditions of the road,” he said.