With the Wednesday, Thursday, Friday storm, the Minnesota Department of Transportation Facebook page offered interesting reading about how snowplows treat the state highways. Posted was the following:
“Minnesota Department of Transportation uses a variety of techniques before, during and after a storm to get the road back to safe driving conditions for you and your loved ones.
Prior to a storm they use anti-icing which is spraying a liquid salt solution on the roadway to keep snow and ice from bonding to the pavement.
Anti-icing is similar to spraying oil in a frying pan to keep food from sticking. This makes it easier to scrape off compacted snow and ice.
During and after a storm de-icing chemicals break the bond between the pavement and ice once it has already formed. The chemicals improve the ability for snowplows to clear compacted ice and snow from the roadways. Road salt (sodium chloride) is most effective above 15 degrees. In very low temperatures, magnesium and calcium chlorides are used (-10 and -20 degrees).
Pre-wetting is a technique that involves treating de-icing salt with salt brine to jump-start the melting process. Pre-wetting also helps salt stick to the pavement. Sugar beet juice or corn syrup are sometimes used for pre-wetting as a corrosion inhibitor and to help the material stay on the road.”
On Thursday, December 27th, the snowplow operators took to the roadways at 3 a.m.
Statistics about snow plows are that they are fifteen times heavier than an average car. Two hundred snow plows in Minnesota are equipped with plow cams. Minnesota Department of Transportation has 800 snowplows with 1,500 full-time drivers. They cover 12,000 miles of state highways and interstates.
Although on Thursday, the precipitation looked to be larger amounts of rain and snow, the wunderground.com Seward Township, Murray County, Minnesota weather station report at 3:49 p.m. was 0.74 inches of accumulated precipitation.
