Q: What is that liquid being sprayed by the CDOT winter maintenance vehicles?

A: Most of the liquid anti-icers and de-icers applied by CDOT are mineral salt compounds in liquid form, such as magnesium chloride, that lower the freezing point of the moisture on the roadways. Magnesium chloride is a naturally occurring element and is extracted from salt-water solutions, most commonly the Great Salt Lake. To extract the magnesium chloride brine, water is removed from the salt water by solar evaporation or other forms of energy, and a simple refinement process, until elements have been extracted resulting in magnesium chloride brine.

Q: What are the big tanker trucks I've seen on Colorado's roads this year?

A: These new trucks are aimed at saving time and money and increasing the efficiency and speed with which CDOT can apply winter road treatments. The new trucks have the ability to cover up to 38 feet of roadway in one pass, reducing the number of times maintenance vehicles must travel the same ground and allowing CDOT to improve road safety much faster than before. This 38-foot area is equivalent to two highway lanes and two highway shoulders wide.

These new tanker trucks are equipped with high technology gauges including infrared sensors, allowing CDOT maintenance workers to make educated decisions about which products and product combinations will work best for any road conditions.

Q: What are liquid anti-icers and de-icers, and how do they work?

A: Anti-icers, or preventive winter road treatments, are liquid forms of salt compounds used to prevent the formation or development of bonded snow and ice for easy removal, and are used before the onset of a winter weather storm. They work by forming a brine that has a lower freezing point than ice and snow.

De-icers, or reactive winter road treatments, are liquid forms of salt compounds used to break the bond of already existing snow and ice. They dissolve downward and penetrate until they reach the pavement. They then fan outward to undercut and disbond the snow from the pavement surface. De-icers melt the ice and snow so they may be easily removed by mechanical means such as plows and are not necessarily intended to clear every bit of ice and snow on the road.

Both anti-icers and de-icers are winter road treatments that work as freezing-point depressants and are the most desirable way to treat winter weather roads.

Q: Why will CDOT increase the use of liquid road treatments?

A: CDOT began using liquid road treatments in the winter of 1995/1996, and has been conducting research since then to determine their effectiveness, safety and efficiency. CDOT has opted to increase use of liquid road treatments as a direct result of their widespread benefits. Reductions in costs, lives lost and winter road accidents, along with increases in driving safety, road navigability and environmental safety have made liquid road treatments the product of choice. Liquid de-icers cost less, work better and cause less damage than any other method available for winter road treatment.

Q: What are the benefits of liquid anti-icer and de-icer techniques?

A: There are numerous benefits to using liquid anti-icer and de-icer techniques. Advantages of these solutions on roadways at higher elevations include reduction in the use of salt and sand mixtures and improvement of road conditions during storms beyond what is possible by the use of sand and salt mixtures alone.
Since CDOT began using these products, they have reduced the consumption of sand used for winter road treatment in Colorado by 23%. This results in cleaner air and vastly reduced PM10 (particulate matter contributing to Colorado's "brown cloud" effect).

Liquid anti-icers and de-icers have less negative impact on highway bridge decks, trees and vegetation, and water supply than any other method of winter road treatment utilized in the past. Liquid anti-icers and de-icers are the best products available for preserving the environment.

Since increasing use of liquid anti-icing and de-icing products, there has been a significant reduction in the number of winter days that state highways are closed due to inclement weather.

Liquid anti-icing and de-icing technology has resulted in cost savings for the state, taxpayers, consumers and corporations. Money has been saved due to energy savings in fuel, reduced wage loss due to tardiness and absenteeism, and reduced production and delivery losses. Lives have been saved by reduced accidents and reduced response time to medical emergency.

Snow, ice and slush related accidents have also been drastically reduced statewide since the winter of 1995/1996 when CDOT began widely using liquid anti-icers and de-icers. Such reductions include a 76% reduction on I-70 west of Glenwood Springs in South Canyon, a 53% reduction on I-70 in the Vail area, a 89% reduction on SH 82 near Basalt, a 53% reduction on I-25 at the Mousetrap and a 64% reduction on I-70 at the Mousetrap.

Q: How do these liquid treatments affect the environment, my automobile and electrical utilities?

A: CDOT has completed a three-year study into the effects of magnesium chloride on the roadside environment and has found that the product does not significantly harm aquatic or plant life. In fact, the sand/salt mixture used in the past can be more damaging to aquatic life as large amounts of silt are washed into streams. The product does not add air pollutants to the environment and improves air quality by offsetting usage of sanding material. CDOT requires all vendors and suppliers of liquid road treatment products to meet the specifications designated by its research.

As with any form of winter road treatment including sand or salt, liquid anti-icer and de-icer residue should be removed from vehicles with soap and water following winter weather storms. Liquid anti-icers and de-icers are no more damaging to the finish of vehicles than conventional sodium chloride-based products and will wash away with a commercial car wash cleaning. Unlike sand/salt mixtures, the liquids will not damage your car's paint job or windshield.

According to utility companies in Colorado, the insulated "grounders" on electrical poles located along well-trafficked highways can become coated in liquid road treatments that become airborne through contact with fast moving vehicles. This can cause shorts when allowed to build up over time. CDOT is working with utility companies across the state to communicate the need for occasional maintenance to remove any build up of the product and thus reduce the risk of outages.

Q: Where in the state will liquid de-icers be used?

A: CDOT will use liquid winter road treatments on most state highways in Colorado throughout the winter weather months. This will include Interstate 25 and Interstate 70 statewide, and will also include all state highways including those that bisect metro areas. Other de-icers, including traditional sand and salt and Ice Slicer, will continue to be used on highways as well. CDOT crews will determine the appropriate de-icer solution based on a variety of weather related factors as well as roadway usage.

The maintenance of metro area streets statewide, including snow removal and snow and ice treatments, usually falls under the jurisdiction of the local municipalities. In some cases, local jurisdictions even provide winter road maintenance for city streets that are also state highways. For example, the City of Denver is responsible for winter road maintenance on portions of SH 88 (Federal Boulevard), SH 40 (Colfax Avenue), SH 33 (Larimer/Lawrence Street), and SH 2 (Colorado Boulevard). The city of Aurora is also responsible for portions of SH 40 (Colfax Avenue) and SH 30 (6th Avenue). The City of Englewood is responsible for winter road treatment on SH 75 (Broadway between Hampden and Belleview), and the City of Brighton treats portions of State Highway 51. Please contact your local government for additional information on local winter road treatment programs.