Why road salt is ‘virtually worthless’ in extremely cold temperatures

Salt is primarily ineffective at melting ice in below-zero temps

Dangerously frigid temperatures are sweeping across Metro Detroit, prompting many school closures until at least Thursday.

And if you are out on the road, you may have noticed salt trucks’ more concentrated approach to salting the streets.

Local 4’s Bryan Schuerman has more on how salt companies are dealing with the brisk air.

“We’re only salting during the day while the sun is up in very select situations,” said Craig Bryson, the senior communications manager for the Oakland County Road Commission.

That’s the message from road crews in Oakland County, which are hard at work with routine maintenance despite the bitter cold temperatures, but they are salting the roads on a case-by-case basis.

“Our big concern is that if we put any salt down, it won’t work, and if it has the lucky shot of working a little bit, it will just cause refreeze, and the water will quickly turn back into ice,” said Bryson.

Most of the region woke up to another light blanket of snow, so the big question is with more snow in the forecast is: Will salt work on the roads with temperatures as low as they have been?

“Why salt is ineffective when the temperatures get this low... It simply just does not melt the snow. I don’t know the science behind it, but it won’t melt the snow. When we get down into the single digits it becomes very ineffective, below five... It’s virtually worthless,” said Bryson.

If you’re wondering if road crews will be able to be ready for the school buses on Thursday morning, the best advice: prepare for anything

“Thursday, we should be able to do some salting during the day at least, we’ll get things in decent condition, but we just urge people to use caution, please assume there may be some icy spots out there, slow down, drive with extreme caution, and we’ll all get through this rough weather patch together,” said Bryson.

Salt is most effective when temperatures are in the mid to upper 20s and lower 30s where it can melt the most ice, the lower the temperature, the less impact the salt has to where we get into the single digits and below zero, salt is primarily ineffective when road crews are fighting winter weather.


About the Author
Bryan Schuerman headshot

Bryan became a permanent member of the 4Warn Weather Team in March 2023 after coming to Local 4 in May 2022 as a freelance meteorologist.

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