It looks like ICE and SNOW is coming to Virginia tomorrow. Wondering what the Virginia Department of Transportation (VDOT) is doing for drivers? VDOT will do pre-icing, pre-treatment, and then de-icing. They will plow the major roads first of snow (if needed) and then move on to secondary roads. VDOT will not plow private roads. Below is information on what VDOT uses for treating roads for ice and snow. PLEASE REMEMBER that if you have a 4WD, that will NOT help you drive on ice... only snow. Please be careful out there!!!
HOW THESE ROAD TREATMENTS DIFFER
- Pre-treatment: A form of anti-icing where chemicals are applied to the road up to 48 hours before a winter storm. This prevents a bond from forming between the pavement and the snow and ice
after the storm starts.
- Anti-icing: Application of chemicals to roads before a snowpavement bond occurs when the temperature drops. Anti-icing emphasizes prevention.
- Pre-wetting: Involves treating the dry de-icing chemicals with liquids before they are applied to the roadway as part of the de-icing efforts. This accelerates the activation of the chemicals before they
are applied to the road. Pre-wetted chemicals typically are not applied to roads before snow or ice accumulates.
- De-icing: The practice of removing snow or ice once it has bonded to the pavement. This involves plowing and continual application of chemicals and abrasives. Plowing generally begins when an inch or more of snow has accumulated on the road.
CHEMICALS USED TREAT ROADS IN WINTER
- Sodium chloride (salt), magnesium chloride, calcium chloride, calcium magnesium acetate and potassium acetate are chemicals used to prevent and remove snow and ice from roadways.
- The Virginia Department of Transportation (VDOT) uses liquid magnesium chloride, calcium chloride and sodium chloride for anti-icing and pre-treatment. Liquid sodium chloride (brine) is an economical anti-icing and pre-treatment chemical. (Those are the white squiggly lines you've seen on the roads since yesterday)
- Sodium chloride and calcium chloride in dry form are used for de-icing but can be used in some cases for anti-icing.
- Sodium Chloride (salt): Dry sodium chloride is VDOT’s primary snow-removal and ice-control chemical. It is applied directly to the pavement once a storm starts. Salt is sometimes mixed with sand before it is applied to the road.
- Dry salt is most effective after snow has accumulated about an inch and the temperature is 20 degrees Fahrenheit or higher. If the temperature is below 20 degrees, salt may not melt enough snow and ice to form a barrier between the pavement and the snow, and it could even produce more ice as melted snow refreezes. At these temperatures, abrasives such as sand are put down to break up ice and increase traction.
Magnesium Chloride and Calcium Chloride:
These products can melt ice at lower temperatures than salt. Both chemicals in liquid form can be used for anti-icing. In its dry form, calcium chloride is used only as a de-icer.
WHEN AND WHERE WILL VDOT USE ANTI-ICING?
VDOT may use anti-icing when snow or an ice storm is predicted and when pavement temperatures are above 20 degrees Fahrenheit. Anticipated temperature and type of precipitation at the start of a
storm will determine its use. VDOT’s anti-icing program covers at least 200 miles of roads in each of
its nine districts. VDOT also deploys anti-icing crews to major bridges, overpasses and areas prone to freezing to keep ice from forming.
WHAT SHOULD I DO IF I COME UPON A VDOT ANTI-ICING TRUCK ON THE ROAD?
If you see an anti-icing crew spraying chemicals on the road, slow down. For proper application, crews will be driving slower than highway speeds. Do not follow the trucks too closely, as the chemicals are slightly slippery for the first 30 to 45 seconds they are on the pavement. If you must pass an anti-icing truck, do so carefully. It is a good idea to wash your vehicle if it comes into contact with these chemicals to protect its finish.
WHAT AREAS ARE MORE PRONE TO HAVE ICE?
Ice can form sooner on the decks of bridges and overpasses before a roadway freezes because air circulates both above and below the surface of the elevated surfaces, causing the deck’s temperature to
drop more rapidly. Ice also can form in shaded areas. Motorists should always use caution and expect slippery conditions when driving during winter weather.
WHAT IS “BLACK ICE?”
Black ice, also known as “glare ice” or “clear ice,” refers to a thin coating of glazed ice on road. While not truly black, it is transparent, allowing you to see the asphalt pavement through it. Black ice often
occurs along with wet roads, making it hard to see and especially hazardous for driving or walking.