You know that adage about how most accidents happen close to home because drivers let down their guard? Similar lapses in vigilance happen in winter. Drivers worry when a big storm is on the way, but most accidents occur in less than 2 inches of snow.

“It’s easy to decide to slow down or even stay off roads buried in a foot of snow or shiny with accumulated ice,” says the National Weather Service’s Milwaukee/Sullivan forecast office, which serves central Wisconsin. “It’s more difficult to pick out subtle differences in conditions, especially if roads were clear just minutes before.” Northern Illinois University researchers Stephen Strader and Walker Ashley note that “minor” winter events are more deadly than big storms.

That’s one reason minor events are so stressful. Another is their variability. “Less than 2 inches” includes freezing rain as well as a quick-hitter that dumps a little in a very short (and usually inconvenient) time. You handle 1 inch that falls during a Friday-evening commute much differently than 1 inch that falls late Saturday night.

We have more options than ever for customizing our response. Wetting with brine before application (prewetting) makes salt stick to pavement instead of bounce off the road into the ditch. Wetting pavement before and/or during an event (anti-icing) slows the process of precipitation bonding to pavement. Applying brine after a storm (deicing) speeds the removal process by weakening the ice/pavement bond. The latter two activities are called direct liquid application (DLA).

We also have more options than ever for improving the effectiveness of all three. More agencies are making their own brine: a solution of salt and water that cost-effectively improves response by minimizing waste. Vendors are introducing more additives that increase brine’s effectiveness. However, each treatment is affected differently by pavement temperature, air temperature, humidity, and precipitation rate and type. If you don’t know your product’s application and working limitations, you won’t get the most out of your materials investment and could inadvertently create more problems for your crews.

I can’t say it enough: Know your product.

Prewetting: least-expensive option

Road salt – sodium chloride – is the cheapest and most-effective way to break the pavement/precipitation bond, but needs moisture to work. That’s why prewetting is particularly helpful in very dry snow and in low-humidity climates: It kick-starts the melting process. It also helps keep a light snowfall from becoming a slick, slushy glaze during rush hour when you haven’t had time to anti-ice.

Brine is a 23.3%/76.7% solution of salt and water (adding more water lowers brine effectiveness). Because it contains water, brine freezes when pavement temperatures fall below 15 degrees F. Thus, if you’re prewetting with straight brine, applications become less effective the closer the pavement temperature gets to 15 degrees F.

Same thing if you’re using brine as anti-icer before or during a storm: It’ll retard but not stop the formation of ice. According to the Ohio Local Technical Assistance Program Center, brine anti-icer should be reapplied every two hours during a snowfall to keep black ice from forming.

Available as a solid or liquid, adding calcium chloride to brine increases costs by roughly 50 cents per gallon but extends the blend’s freezing point to below zero. Calcium chloride is most effective on pavement that’s less than 28 degrees, so it can be overkill on warm-temperature events.

Agricultural-based additives also extend freezing point, though not as far as calcium chloride. However, because they don’t contain salt, they have less impact on the environment – an important consideration in areas of the country where regulators are imposing total maximum daily limits (TMDLs) for chloride in groundwater.

Weather wreaks havoc in many ways

Precipitation type and intensity affects any decision about what strategy to deploy. Freezing rain could wash away the brine or brine blend on prewet salt before it can provide any benefit; on the other hand, the liquid lessens bounce and scatter by weighing down the salt granules. Only you can determine which scenario is most cost-effective for your situation.

Similarly, there’s no point in anti-icing when freezing rain is predicted because material would be diluted or washed off the pavement. Flow charts and pre-application guidelines developed by the American Public Works Association aid the anti-icing decision-making process. In certain circumstances, one application may be enough to do the job, saving on labor and material costs and vehicle/equipment wear and tear.

As beneficial as anti-icing can be, it also can work against you. I’ve seen instances where the only thing very-low-moisture-content snow stuck to was the anti-icer on the road. Again, you must know your material, its application rates/limitations, and if application can be done per your level-of-sevice (LOS) goals.

Our search for a dual-use liquid

We’ve been making brine since 2004. We’ve been blending brine with additives including Beet Heet (K-Tech Specialty Coatings Inc.; Ashley, Ind.), GeoMelt 55, and ThermaPoint R (ready-to-use concentrate, not blended with brine) and ThermaPoint S (Wilkinson Corp.; Mayville, Mich.) since 2016. Our goal is to find one formulation we can use in most minor events to pre-wet and anti-ice.

Our seven front-line vehicles are equipped with a:

We’re running an experiment with two trucks running straight calcium chloride; we’re also testing ThermaPoint R and different blending percentages with Beet Heet. Metropolitan Chicago has had a light winter, so we haven’t been able to come to any solid conclusions.

I appreciate honesty from vendor sales representatives about their product’s capabilities and limitations. We’ve had issues with concentrates creating sludge and crystalizing in storage and application tanks. We moved away from those because I want a stable product that takes minimal effort once it’s in my 6,000-gallon bulk tank.

In the end, including liquids in your winter maintenance program can help your agency achieve better service levels sooner -- when used correctly. Whether you’re thinking about starting a program or expanding one, a vast amount of information is available. Aside from vendors, don’t hesitate to contact agencies already using liquids. They will be able to share their successes (and failures) to help you.