Paul Shahen
Eyewitness News Reporter

Chattanooga, TN (WRCB) -- City and state road crews have known about the threat of winter weather for quite some time.  And they've been preparing all week.  Today, they set their final game plans for when it hits.

As you know snow in the Tennessee Valley is a rarity but when it comes, city and state road crews can't take it lightly.  That's why they've spent all week preparing for whatever tomorrow morning has to offer.

The snow may not come until Thursday morning.  But city and state road crews spent all day preparing the roads with a substance called brine.  It's a combination of water and rock salt, that prevents snow from freezing on the road.

Tony Boyd for the city of Chattanooga says, "we work pretty close to the state, they do a lot of this too. They've gotten really good results on bridges and over passes up to 24 hours before an event."

Road crews say bridges and overpasses are a big emphasis point when laying down the substance.  Mainly because air can freeze the road from below and above the ground at the same time.  The trick is laying the brine down when the temperature is right, because they don't want it to freeze..

"If you put brine down it's good to about 20 degrees. But if it re-freezes, brines on the road, snow melts and re-freezes, then we have ice and that's even worse," says Jennifer Flynn of TDOT.

Worse because you can see the snow while driving, but by the time you see the ice, it may be too late.  So even if the road your on has been taken care of by the road crews, please use caution.  But do know both TDOT and public works of Chattanooga are using all the recourses they have necessary to take on whatever tomorrow has to offer.

Boyd said, "We've got available up to 30 trucks that we can put the salt and sand in, to spread at that point."

We have all our men and women we can use," says Flynn, "they're on standby at times like this. So we use as many people as we need to."