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A guide for matching the right anti-icing product to the particular winter storm conditions you’re facing.

May 16, 2022

If you follow reliable storm forecasts, crews can deploy before snow even begins to fly. A pre-treatment of liquid anti-icers can effectively prevent snow from bonding to the pavement.

Winter storms take on a variety of different forms. Whether it’s ice storms, thick powder, slush, blinding blizzards, or a mix of conditions, our goal must be the same...clear roads fast. However, not all deicers are effective in all storm scenarios. Let’s talk about how to choose a road treatment product based on storm conditions.

Step 1: Use Reliable Weather Forecasting

According to the Western Transportation Institute (WTI), snow fighting crews using reliable weather forecasting experience more efficient use of manhours, including less overtime and shorter work cycles. In addition, reliable forecasting affords a more timely snow fighting response, including pre-treatments. As well as and more responsible deicer product usage which is better for drivers, budgets, the environment, and infrastructure.

There are a lot of weather forecasting apps out there, and the best of them rely on data from the National Oceanic and Atmospheric Administration (NOAA). NOAA’s Weather Prediction Center has a selection of forecast tools snow crews can use to see what they are up against and plan their response.

During high-wind conditions, snow and ice managers should consider using pre-wet granular deicers to reduce product, and do not use round pellet deicers prone to bouncing and scattering off pavement surfaces.

Step 2: Combine Weather and Road Data

Atmospheric data is only a piece of the puzzle. Effective snow fighting requires an understanding of both weather and road conditions. Data from a Road Weather Information System (RWIS) can help crews read “real-time” conditions on the ground. RWIS is a centralized hub that collects road sensor readings. This data is combined with weather data to create a “nowcast” of conditions in a specified area. According to WTI: “the use of RWIS technologies can improve the efficiency and effectiveness as well as reduce the costs of highway winter maintenance practices.”

What near real time environmental data do you need?

  • Air temperatures
  • Wind speed and direction
  • Precipitation type and amount
  • Pavement temperatures
  • Bridge temperatures
  • Pavement conditions
  • Micro-climate data (large water sources near roads, road elevations, perma-shade, snow fence locations)

Step 3: Select The Best Road Treatments

When it comes to choosing a road treatment, it is important to plan and not just react. It should be noted that road aggregates like sand and gravel are not deicers or anti-icers. They don’t lower the freezing temperature of ice and snow and are not included in the following content.

Here are some general guidelines to consider when choosing which treatment to use.

Anti-icing/Pre-treatments.

If you follow reliable storm forecasts, crews can deploy before snow even begins to fly. A pre-treatment of liquid anti-icers or light applications of solid deicers can effectively prevent snow from bonding to the pavement to begin with. When to use:

  • Before any and all ice storms
  • Before snowstorms at night
  • Before snowstorms predicting heavy precipitation rates

Temperature Ranges. Not all deicing ingredients can work efficiently at all temperatures. Remember, air temperatures and pavement temperatures differ most of the time; it is important to take both into consideration

Over 20° F — Anti-icers or solid deicers that contain sodium chloride, potassium chloride, calcium chloride, or magnesium chloride

Under 20° F — Anti-icers or solid deicers that contain calcium chloride and/or magnesium chloride

Variable Temperatures (when storm temperatures fluctuate above and below 20° F) — Anti-icers or solid deicers that contain complex chlorides so they don’t lose efficiency as temperatures rise or fall

Heavy Snowfall. For heavy snow precipitation rates:

  • Use solid, granular deicers with variable gradation (containing some granules large enough to penetrate to the road surface and begin brining)
  • Do not use lightweight, round pellets that have a hard time penetrating to road surfaces
  • Do not use liquid anti-icing treatments after heavy snow accumulates

Windy Conditions. Applying certain road treatments during high winds is counterproductive. Driving winds can prevent some products from reaching the road before they can start working. And during high-wind conditions, consider using:

  • Use pre-wet granular deicers to reduce product waste during high winds
  • Do not use liquid treatments in high winds
  • Do not use round pellet deicers prone to bouncing and scattering off-road surface.