By Jack Fink

(CBSDFW.COM) – Crews from the Texas Department of Transportation and the North Texas Tollway Authority continue working around the clock to keep the roads as safe as possible.

Both agencies say they have tried to make sure at least one lane on each of their highways and toll roads remain clear and their plan is to build upon that.

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Hundreds of people are working 12-hour shifts.

They’re using salt, sand and what’s called MD 20, magnesium chloride, which works well in the bitter cold temperatures.

But we are seeing unprecedented cold here in North Texas, and a spokesman with NTTA, Michael Rey, said drivers must keep that in mind at all times. “We can do the treatment, the heavy salts, the sand, plow things out of the way but still at the end of the day, the surface is frozen.”

The agency’s toll roads have sensors which help them detect ice.

Rey said the sensors indicated just how cold the surface temperatures have been. “We were anywhere from seven degrees with the bridges to 19 degrees with earth insulated roadway beneath it.”

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Wind is another factor, so Rey said the roads need constant attention. “Keep in mind that requires continuous treatment. So the crews continue to stay out. With the blowing snow, it could be where you plow an area and moments later, it has a much different feel because it’s got new snow over it.”

Patrick Clarke, a spokesman with TxDOT Dallas, said, “We‘re out with snow plows, motor-graders, we’re also spot-treating certain areas with icy patches, putting the salt down there.”

The bridges and elevated roadways are first to ice up.

Both Clarke and Rey warned drivers against attempting to pass snow plows and sand and salt trucks.

Rey said if people do drive around their vehicles, they could be driving in slippery and treacherous snow and could find themselves in trouble. “We’ve seen some behavior that’s not great frankly. People passing by. These crews are working slowly, meticulously, as quickly as they can to make that road safer for you to drive on. Please don’t pass them, get too close, and tailgate.”

Clarke agreed. “Drive to the conditions, not the speed limit. You will see our trucks out there treating the roadways, do not attempt to pass them. Slow down. Give them room.”

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He said slow down and be patient, and recommended those who don’t have to be out on the roads to stay home.