Road crews rely on salt brine

December 21, 2003|JIM LOGAN

Kentucky might be 600 miles from the Atlantic Ocean, but you can thank salt water for keeping our roads clear when the weather turns cold.

That's because the state Department of Transportation relies chiefly on salt brine - a mixture of water and salt - to prevent ice from sticking to roads.

As a tool, it's nearly perfect for a cash-strapped state: It's easy to use, it works and it's cheap, just 5 cents a gallon.

To apply salt brine, trucks simply spray it on a road 12 to 24 hours before expected snow. The water will evaporate, leaving tell-tale white lines of salt.


Weather forecasts are key in deciding when to do anti-icing. Salt brine is effective down to temperatures of 20-25 degrees, according Mark Pfeiffer, director of public affairs for the state Transportation Cabinet. Apply it when it's too warm and rain will wash it off. Use it when temperatures dip below 20 and there's a risk ice will bond to the road anyway.

At temperatures colder than that, KDOT will mix liquid calcium chloride - a blend of salt brine and lime - with road salt in a process called "pre-wetting." That solution is used after snow falls. The reason: At 62 cents a gallon, it's expensive.

Currently, KDOT's District 7 in Lexington provides anti-icing on roads only in Anderson, Scott and Fayette counties, according to Bobby Sturgeon, the district's acting chief engineer. Boyle, Mercer and Garrard counties will get anti-icing next year if requested equipment arrives, he said.

"We've got the equipment ordered," he said, "but it seems like we always run one season behind."

Highway engineers use a kind of outside-in approach when anti-icing. Rural roads are done first, then secondary streets, then major highways and bypasses.

"We start with (rural roads) first because we know when it starts snowing, those are going to be the last ones we get to, " Sturgeon said.

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