GDOT's brine truck left agency's Forest Park facility around 8:30 p.m. Thursday evening to start laying down an initial layer of brine on metro roads and highways.

"As temperatures continue to drop, you'll have bands of either snow or sleet hit the road dropping the temperature of that pavement. As that melts and resets as we get that hard freeze, you'll see a lot of black ice spots on the roads," Dale said.

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That's why 11 brine trucks will treat highways from the south metro up to north Georgia, using technology that tracks real-time road conditions, erring on the side of caution.

"Layer after layer that we've added on to make sure that we're prepared," Dale said.

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Driver David Wilkerson is pretty sure his car can handle whatever comes. He told Channel 2's Aaron Diamant that his plan is just to stay in.

“I just stay in the house. That’s the best precaution,” Wilkerson said.

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Sharon Watson’s advice to drivers who venture out overnight is to take it slow.

“Just take it easy and take precautions, and let’s not go overboard. We’re familiar with this,” Watson told Diamant.

GDOT said crews will likely lay a second layer of brine on Friday.

“We accept the challenge of our first winter weather snap,” Dale said.

In Cobb County, DOT division manager for road maintenance, Bill Shelton, said it call comes down to preparedness.

"This is a little early for winter weather," Shelton told Channel 2's Chris Jose. "This is the first time I've known weather like this before Christmas."

Cobb County DOT has already started Thursday afternoon running four trucks loaded with brine. Each carry 800 gallons worth to pretreat bridges and elevated concrete surfaces all across the county.

Shelton told Jose that comes out to about 800 miles of roadway.

“You're not wasting money, you're being proactive and if it's necessary to treat the bridges, we've done it and we haven’t lost anything,” Shelton said.

The county said pre-treating bridges will cost less than $100.

Two years ago, Shelton said Cobb DOT spent $1 million on new equipment, doubling their fleet to 11 trucks.

“We have a brine maker, we have new yard spreaders, we've got new tandem spreaders, we've got the tailgate spreaders, we've got the brine spreaders,” Shelton said. “We are well prepared. We've got some good experienced people. We've got the drill down. We've got the routes optimized to efficiency.”

The county told Jose that it will run a dozen crews on 12-hour shifts if things take a turn for the worst.

How does brine mixture work?

The brine prevents ice and snow from sticking as fast to the roads.

Many viewers have asked Channel 2 Action News about the bring mixture -- the number one question: Is brine safe for the roads? Will the roads begin to crumble in several months or years because of it? DOT leaders said their research indicates the roads will be fine.

In 2015, Channel 2 Action News spoke to GDOT about the brine use.

“Obviously, states up north use this very successfully, and they’re using it weekly during the season,” spokeswoman Natalie Dale said. “We don’t have to use it that much, and we are fortunate because long term, year after year after year, it could cause some corrosiveness to the pavement, but we’re not using it that much.”

Dale also explained that using the brine before a storm means they can put down less salt and gravel during the storm. That rock salt is one reason why we see many potholes after crews have plowed. The brine solution goes down 24 hours in advance.
 
"That gives it time to set on the road, seep into the road, and get just ahead of the storm, to where you have an effective brine treatment (and are) not caught off guard by the storm," Dale said.