Severe winter weather has forced state and local road maintenance crews to use more road salt than anticipated so far this winter season.
Typically, the Ohio Department of Transportation District 11 uses between 48,000 and 52,000 tons of road salt during the winter season, but the district has already used about 47,000 tons of salt with a month left of winter driving, according to Becky Giauque, public information officer.
"We are further into our stockpiles than we would have expected at this point in the year," she said."Our record usage was 55,000 tons."
District 11 covers a seven-county region in Eastern Ohio, including Belmont, Carroll, Columbiana, Harrison, Holmes, Jefferson and Tuscarawas counties. District 11 crews are responsible for 3,300 lane-miles of roads and more than 1,000 bridges utilizing 125 trucks and more than 200 drivers. After a road is first plowed, de-icing chemicals are usually applied in a windrow 2 to 4 feet wide down the middle of a two-lane road.
"We are in no danger of running out of salt," Giauque said. "All seven of our counties have ordered additional salt."
Giauque explained that plain road salt is effectively useless in the subzero temperatures that are expected in our region for the next two days. The ODOT chart for pounds of ice melted per pound of salt at different pavement temperatures shows that at 30 degrees, one pound of salt melts 46.3 pounds of ice. As the temperature drops so does the effectiveness of salt.
"The surface temperature of a snow- or ice-covered road determines de- icing chemical amounts and melting rates," Giauque explained. "As temperatures go down, the amount of de-icer needed to melt a given quantity of ice increases significantly. Salt can melt five times as much ice at 30 degrees as at 20 degrees. The effectiveness of de-icing can change with small differences in pavement temperatures.
In addition, she stated that ODOT uses calibrated salt spreading machines that control the amount of salt distributed according to the snow and ice conditions on the roadways. Additionally, ODOT plow trucks have infrared temperature sensors which allow operators to see the exact surface temperature of the roadways, so they apply the right material.
Using one pound of salt at 25 degrees, the effectiveness drops to 14.4 pounds of ice; at 20 degrees, it's 8.6 pounds of ice; at 15 degrees, 6.3 pounds of ice; at 10 degrees, 4.9 pounds of ice; at 5 degrees, 4.1 pounds of ice; and at zero, the amount of ice drops to 3.7 pounds The time that salt takes to melt one-eighth inch of glare ice increases from 10 minutes at 30 degrees to nearly an hour at 20 degrees colder.
According to ODOT policy, once the temperature drops below 15 degrees, crews will start to utilize calcium chloride or other additives to melt snow and ice. In extreme cold conditions, ODOT combines rock salt with liquid calcium chloride to better melt ice.
This salt additive is effective on roadways with pavement temperatures up to minus 25.
The state is also using a sugar beet juice product called Geo Melt blended with salt brine in Tuscarawas and Carroll counties. The blend has been poured out of tankers in preparation for sub-zero temperatures, coating bridge decks and overpasses in the district since 2007.
The de-icing product marketed as Beet 55 is a natural organic product made from sugar beet molasses blended with calcium chloride.
The manufacturer reportss the mixture reduces corrosion levels by 70 percent, improves longevity of calcium by one to two days and will melt more snow and ice than straight calcium by 10 to 20 percent.
Officials indicate the juice reduces the total chloride load to the environment by 43 percent and does not stains the road or attracts animals.
Giauque explained that this past weekend's snow is not the main culprit for the above average salt usage,
"The little events, the 1 to 2 inches of snow spaced 12 or so hours apart are real salt burners."
Throughout severe winter events, ODOT crews constantly monitor pavement conditions with road sensors scattered throughout the state and treat areas that are re-freezing.
"We're continually monitoring the road conditions and we'll have crews out as conditions warrant," Giauque said.
Even though most Eastern Ohio roads were safe and passable this morning, ODOT is urging drivers to remember, 'in ice and snow, take it slow,'" Giauque said.
With a winter weather advisory and wind chill warning in effect for much of the state through Wednesday, it's important for motorists to understand how quickly wet roads can freeze, creating d0angerous patches of ice. A winter weather advisory means that snow and a flash freeze of wet roads are possible and can cause travel difficulties.
Current air temperature, surface status and temperature, and visibility among other things are easy to view by visiting ODOT's Web site for traffic and road condition information www.ohgo.com and selecting the road sensors icon located on the menu at the right side of the page.