CDOT Maintenance Crews in Boulder, Estes Park, and Longmont Prepared for the Winter Ahead

October 24, 2012 - Northeastern Colorado/CDOT Region 4 - BOULDER, LARIMER AND WELD COUNTIES — Governor Hickenlooper and the National Weather Service have designated this week “Winter Weather Awareness Week” in Colorado.

Appropriately, maintenance crews from the Colorado Department of Transportation (CDOT) in Boulder County and portions of Weld and Larimer counties are prepared for the upcoming winter season. There are 43 maintenance employees dedicated to plowing and de-icing state highways in Boulder, Longmont, Lyons, Estes Park, Mead and Erie.

To help crews combat snow and ice along approximately 1,200 lane miles of highway, a variety of equipment and products will be used throughout the winter, including a new state-of-the-art delineator system to help plow drivers know when guardrail starts and stops. Delineators are the green metal posts with reflectors on them that help label the edges of roadways, but the new delineators will be flexible so they can sustain more damage than ordinary metal ones. CDOT crews will be using a system borrowed from the state of Minnesota that will mark where guardrail starts and stops using black arrows on the reflectors. An upward facing arrow will indicate the start of guardrail and a downward facing arrow will indicate that guardrail has ended. These simple symbols will help plow drivers during tough storms to keep track of the roadway, which will increase safety for all motorists and will also help keep guardrail in better condition, potentially saving money in the coming years.

“This year we are testing the new delineator posts on US 36 between m.m. 0.00 and 20.00, On State Highway (SH) 7 between 19.30 and 33.47, and on SH 119 between 26.00 and 40.75,” said CDOT Maintenance Supervisor Chris Kelly. “The posts will look a little different from anything motorists have seen in the area, so we wanted them to know exactly what they meant and how they would be helping the traveling public.”

CDOT always treats and plows primary roads first such as I-25, US 36, US 34, State Highway (SH) 119 and US 287. Secondary routes include SH 7, SH 42, SH 52, SH 66, SH 72, SH 93, SH 157 and SH 170.  Highway segments with an annual average daily traffic (AADT) count less than 1,000 will experience limited snow removal operations. For the most part, CDOT crews will maintain these highways 14-hours a day, from 5 a.m. to 7 p.m. (exceptions may be granted for school bus routes, highway segments with high accident rates or hospital/emergency routes). To see a complete list of highways with limited plow coverage,

To help maintenance crews combat the snow and ice, CDOT will still continue to use liquid de-icers, solid de-icers, and a sand/salt mixture. The two main types of liquid de-icers that will be in used this winter are magnesium chloride and cold temperature magnesium chloride. Magnesium chloride* is effective at pavement temperatures above 16 degrees Fahrenheit while cold temperature modified magnesium chloride* is effective for pavement temperatures below 16 degrees Fahrenheit. Trucks are equipped with infrared sensors to monitor ambient and pavement temperatures throughout a storm.

The two types of solid de-icers that will be used are Ice Slicer and North American Salt. Both are granular salts mixed with magnesium chloride. Ice Slicer is primarily used for pavement temperatures 20 degrees Fahrenheit and below while North American Salt is primarily used for pavement temperatures above 20 degrees Fahrenheit. In some areas, crews will mix the solid de-icers with sand for increased traction.

To disperse these various products, the maintenance crews will use 45 pieces of snow removal equipment. Of the 45 pieces, 30 are snow plows used to apply solid and liquid de-icers. There are also eight loaders and two motor graders for the removal of heavy or large amounts of snow. Crews use four sweepers to clean up material following snow storms.

Maintaining clear roads on bridges, overpasses and tunnels is often a challenge, but to help crews, eight automatic de-icing systems will be operational this winter in the following high traffic volume locations:

  • State Highway 119 over the St. Vrain Creek near Longmont
  • State Highway 52 over I-25
  • State Highway 66 over I-25
  • Three systems on US 34 over the Big Thompson River between Estes Park and Drake
  • Three systems on I-25 between Weld County Road 20 and State Highway 66

All of the systems are designed to automatically spray liquid de-icers when the on-site sensors detect a decrease in surface temperature among other conditions such tire grip, type of moisture and depth of moisture.

The automatic de-icing systems are not the only technology tool that Boulder area maintenance crews rely on. In fact, there are 23 snowplows that are equipped with technology that will help drivers determine the appropriate treatments for a roadway. The Maintenance Decision Support System (MDSS) combines advanced weather prediction, advanced road condition prediction and rules of practice for anti-icing and de-icing to generate road treatment recommendations on a route-by-route basis. The goal of MDSS is to provide more effective use of maintenance resources and increase safety, reliability and mobility on roadways.

This MDSS system allows crews to input real-time conditions, including road and ambient temperature, type of snow removal products being used and the application rate. After comparing the information to 15 weather reports, the system will then provide suggested treatments based on the information and models. The system may tell the operator to re-treat the road at a later time, apply different products at different rates or even to continue current procedures. The suggested treatment can then be followed or the operator can override the system.

Last year, CDOT used approximately 171,708 gallons of liquid de-icer, 1,708 tons of solid de-icer and 2,272 tons of sand and slicer mix. Crews also plowed 111,984 lane miles in Boulder and portions of Larimer and Weld counties.

While CDOT is prepared for the winter ahead, it is also important for motorists to be prepared. CDOT strongly encourages motorists to plan ahead by visiting or by calling 511 anywhere in Colorado. Current road and weather conditions are available 24 hours a day, seven days a week.

You can also sign up for e-mail and text message alerts by visiting and clicking on the green cell phone icon in the upper right corner under the search function. You can subscribe to any of the lists for free and there is an entire list dedicated to northeast Colorado.

Here are a few winter driving tips to remember:

  • Be sure your windshield wiper fluid reservoirs are full as liquid de-icers may stick to your windshield
  • Let the snowplow drivers do their jobs by giving them extra room and don’t pass them on the right.
  • Slow down! Even roads that have been treated with liquid de-icers may be slippery.
  • Be prepared. Have a scraper, snow brush, coat, hat, gloves, blanket, first aid kit, flashlight, tire chains, water, and nonperishable food in your car.
  • Make sure your tires have good tread.

For more information about CDOT’s snow removal plan including equipment and products, visit

**Snow Removal Products:

Magnesium Chloride in solutions up to 30% - Effective for use down to 16 degrees Fahrenheit pavement surface temperature.

Cold Temperature Modified Magnesium Chloride in solutions up to 27% magnesium chloride - Used when surface temperatures fall below approximately 15 degrees Fahrenheit. Products meeting this description have a corn byproduct additive that greatly lowers the freezing point of magnesium chloride.

Ice Slicer and North American Salt - A solid product that is mainly sodium chloride with small amounts of other materials that help this product work at lower temperatures than pure sodium chloride. It is used to melt ice pack at curves and intersections and other spot locations that make it difficult to de-ice with liquids.