The Oregon Department of Transportation is testing the use of salt to clear some of the state’s highways of heavy snow and ice accumulations.
Rock salt is widely used in the Midwest and Eastern parts of the country to improve winter driving conditions, but has significant negative impacts on the environment and on vehicles—in the form of rust.
During a recent visit to ODOT’s Bend vehicle maintenance station, we were shown a new combination snowplow and sanding vehicle that is specially equipped to spread rock salt on Interstate 84 in the Columbia River Gorge.
“Salt is a great tool and really helps to melt snow but it’s always a cost-benefit analysis with the right tool, at the right time, at the right place,” said Kacey Davey, ODOT public information officer.
ODOT began experimenting with rock salt ten years ago on I-5 over the Siskiyou Summit and U.S. Highway 395 in southeast Oregon.
In both locations, rock salt was found to be highly effective at melting compact snow and ice down to to bare pavement within a few hours.
“The use of salt is a newer tool in the state of Oregon so we are trying it on our big busy highways first and it might spread throughout the rest of the state at some point,” Davey said. “But use salt in our area would require millions of dollars in new infrastructure, places to store the salt, special equipment to run the salt and we just don’t have that at this time.”
The salt application pilot project concluded salt was effective in maintaining roads, reducing crashes, and improving mobility, thus its use was expanded to Interstate 84 in the Columbia River Gorge.
But in high use areas there have been noticeable increases in salt concentrations in nearby streams.
“When you have the big rock salt, it’s stored in large piles kind of like our big cinders are. But where our cinders are stored out in the open and they can be snowed on and rained upon, salt can’t get wet or it hardens and lumps together. It has to have its own shelter to be stored in,” Davey said. “As far as the equipment used to spread the salt, that has to be all stainless steel because salt is corrosive to vehicles.”
ODOT’s winter maintenance strategy calls for the use of salt where and when it is critically needed when other tools, such as the liquid deicers currently sprayed on Central Oregon’s highways, are ineffective.