By Harley Nefe
Department of Transportation employees work around the clock to ensure roads are treated for travel throughout the winter weather in their areas. As these weather conditions may be coming to an end this season, the local DOT has provided insight about its operations.
The North Carolina DOT has more than 3,200 specially-trained employees and more than 1,900 trucks that can be used to remove snow and ice. Preparations for road treatment are handled by the DOT maintenance yard in each county.
Locally, NCDOT Watauga Maintenance has 21 full-time employees including administrative staff. An additional 4-5 employees from other NCDOT units assist Watauga Maintenance during snow removal.
Maintenance crews begin preparing for the winter storms in the fall, months prior to the first winter storm. Preparations include cleaning, repairing and testing equipment, reviewing snow removal routes and stocking up on necessary supplies like salt, sand, salt brine (mix of salt and water) and aggregate screenings (crushed gravel or stone).
The NCDOT can store up to 175,000 tons of salt and sand and 2 million gallons of salt brine total at its storage facilities combined. In a typical winter, North Carolina uses between 50,000-60,000 tons of salt.
The Watauga Maintenance’s facility maintains storage capacity for 5,300 tons of salt, 10,000 gallons of salt brine and 500 tons of aggregate screenings.
Watauga Maintenance used approximately 4,200 tons of salt, including the material used to make salt brine, during last year’s winter, and they also used approximately 1,000 tons of aggregate screenings.
Watauga County’s DOT Maintenance Engineer Travis Chrisawn said they are on pace to use 2.5 times those quantities this winter.
“We have used a significant amount of salt and screenings this winter due to frequent snow events,” Chrisawn said.
Salt usage and deliveries are an ongoing process during winter months, and the total usage is calculated at the end of the winter season. However, when compared to previous winter seasons, it can already be noted that this year is different.
“This winter has been the most active in recent memory,” Chrisawn said. “The winter of 2010 was challenging, though, this winter has experienced snow events more frequently.”
The DOT receives weather forecasts from the National Weather Service, and the decision to pretreat roads is made 24 to 48 hours before a storm. If it’s around 32 degrees and frozen precipitation is in the forecast, roads are typically pretreated, unless it’s raining because the solution will get diluted and be washed away.
Salt is used to treat icy and snowy conditions after a storm because it dissolves in the layer of liquid water on the surface, lowering the freezing point below the ice’s temperature, which causes it to melt.
Salt brine is generally what the DOT trucks spray on the roads before a storm to keep ice from sticking to the pavement. Salt brine can be used in temperatures as low as 18 degrees; however, below that, it is less effective. It costs 15 cents a gallon to make, which means DOT crews can treat a mile-long length for about $6. This amount can be compared to the $14 it costs crews to use rock salt on the same length of road after a storm.
Sand and aggregate screenings are also used to treat road conditions, as they act as an abrasive and provide extra traction between ice and tires. Typically, a salt and sand mixture is applied to bridges and shady areas.
When it comes to how roads are prioritized, interstates are treated first, then four-lane-divided primary roads that have U.S. or N.C. in the name. These types of roads are prioritized because they are essential to regional or cross-state travel. After the primary roads get treated, next comes the high-volume secondary roads, followed by the lower-volume secondary roads and subdivision streets.
The NCDOT maintains approximately 1,100 lane miles in Watauga County. These areas are divided into 11 maintenance routes for snow removal purposes.
“Most routes are assigned two trucks, though we often use a third truck on the divided section of US-421,” Chrisawn said.
Watauga Maintenance has 17 CDL (Commercial Driver’s License) trucks outfitted for snow removal. In addition, the DOT utilizes privately-owned trucks to supplement the fleet during significant events. The decision to bring in privately-owned plow trucks depends on weather forecasts and roadway conditions.
The NCDOT budgets $60 million a year for storm preparation and snow and ice removal. If the budgeted amount is exceeded, additional funds are taken from emergency reserves.
DOT crews are on standby to work whenever needed, and they consistently work before, during and after a storm to treat troubled areas.
“Watauga County Maintenance crews often work long hours during snow removal,” Chrisawn said. “We split our work crews into a day shift and night shift to ensure coverage 24 hours a day until roads have been cleared. This includes providing snow removal during weekends and holidays. NCDOT Maintenance employees are a dedicated group that often face challenging and hazardous weather conditions to provide a safe roadway for the traveling public.”