Appreciating the High Technology of Salt Trucks

Record snowfall has covered the U.K., while cold temperatures are gripping Europe.  Seoul and Beijing have seen their heaviest snowfalls in recent memory, and arctic temperatures have penetrated the U.S. far enough to threaten crops in Florida.  For those who have to commute to work in such weather, this is a good time to appreciate the technology incorporated into winter service vehicles.

Sand- and salt trucks have evolved a long way from the era when two men with shovels used to stand on the back of a dump truck. Modern grit is a mixture of sand and rock salt, but the latter has deleterious effects not only on metal vehicle frames, but also on vegetation and freshwater lakes and streams.  A variety of techniques have therefore been devised to keep roads on a "low-salt diet."

"Pre-wetting" the salt -- spraying it with brine as it's dropped -- helps it stick to the road better, meaning crews can cut back from 500 pounds per mile to 200...

Vehicle-mounted electronic thermometers let supervisors know how far above or below freezing the pavement is. Some truck cabs have up-to-the-minute weather radar so crews know how long it'll be before the freezing rain or snow hits...

To prevent the grit from being thrown off the road surface by vehicle tires, additional substances may be intermixed to increase adherence.  The earliest additive was molasses, but it was difficult to use in cold weather and tended to attract cows and wildlife to the roads.

That means using brine, magnesium chloride and a sugar beet byproduct, which are mixed via a dozen yellow-handled valves marked with letters of the alphabet.

Fine-tuning the grit application to the weather conditions not only saves taxpayers money (one truckload of salt costs ~$800), but also reduces chloride levels in nearby lakes.  Photo credit Richard Tsong Taatarii, Star Tribune

Newest 5
Newest 5 Comments

Molasses? What a mess that would be. I never had any idea so many different ingredients were mixed into the stuff. At least I know they are trying to be more environmentally responsible while increasing my safety and decreasing the structural stability of my car's unibody.
Abusive comment hidden. (Show it anyway.)
Interesting article. Here I thought the salt people were just dumping the salt willy-nilly. Hmm

Plowing is great and all; it must be cheaper and better for the environment. But it won't keep roads clear for long in a decent snowfall. I've never seen how pumice works, but it sounds like it could be a cheap alternative for places that have it in good supply.
Abusive comment hidden. (Show it anyway.)

Your blaming Global Warming for the amount of snow in the UK?

So what do you call the amount of snow that hit us in the late 80's and 60's?

Also what about many many many years ago when there was a mile of ice over the UK?
Abusive comment hidden. (Show it anyway.)
Salt also has a tendency to remelt and refreeze lower when it gets colder, causing cracks deeper below. There was an electrical fire on my block a few years ago... the salt from over the years sank low enough, refroze and sat on top of electrical wiring providing the mains for the block we were on. Ate away the insulation and cut power to 50ish homes during one of the worst freezes we had in that area. Not fun. It's still a necessary evil... as not salting anything would just do much more damage to everything (not to mention what would happen to people and cars on those surfaces). Not surprisingly, car wash places tend to do really well during the winter when the days break above freezing... offering hot soapy water rinses for the underside of cars as well.
Abusive comment hidden. (Show it anyway.)
Login to comment.

Email This Post to a Friend
"Appreciating the High Technology of Salt Trucks"

Separate multiple emails with a comma. Limit 5.


Success! Your email has been sent!

close window

This website uses cookies.

This website uses cookies to improve user experience. By using this website you consent to all cookies in accordance with our Privacy Policy.

I agree
Learn More