NASHVILLE, Tenn. (WKRN) – With the winter months fast approaching, Nashville’s roadways are always the biggest concerns when snow and ice hit.
The Tennessee Department of Transportation uses a certain process to keep the roads clear. That process starts with salt brine.
“If it’s going to come in quick as a dry snow, [or] what not, we’ve got time to do the salt brining that many people see,” explained Mike Brown with TDOT. “ Our whole school of thought on that is that the brine gets out on the road as a liquid, and
then that liquid evaporates out and then we have the dry salt residue. So we’re brining when we know that there’s not going to be a lot of rain come in prior to the rain changing over to snow.”
If there is a lot of rain before snow, TDOT has a process for that, too.
“Before it gets down to freezing temperatures, then we’re going ahead and putting out some granular salt out on the road. And then, obviously with the rain and the granular salt, that’s kind of making brine naturally,” explained Brown.
Over the last several years, TDOT has also added a new trick to their process.
“If it’s going to be extremely cold, say in the mid to upper 20s, we may even pre-wet the granular salt with a chemical called calcium chloride. It allows us to lower the eutectic temperature. That means it gives it more melting power and strength at lower temperatures,” Brown said.
TDOT says that process works until the temperature gets down to around 15 to 18 degrees.
In addition to the salt and brine, the department also has snow plows and this year they will utilize trucks that have a plow underneath them in the center of the truck, as well as the front.
“What we’re looking at is some new technology that we’re using. This is called an under body plow. It has hydraulic cylinders that allow this plow to be pushed down and create more downward pressure to give us more ice cutting ability,” Brown said.