CDOT Announces Winter Maintenance Plans for the Denver Metro Area

The plan includes using four primary types of snow removal equipment, various anti-icing and de-icing products and three automatic bridge de-icing systems for prompt and effective snow removal.

“While the number of employees and equipment has remained the same over the years, we have added additional tools to help us keep our Denver area highways safe,” said CDOT Executive Director Russ George. “Our crews will continue to work 12-hour shifts during snow storms and that means we will have crews out day and night on weekdays, weekends and holidays to ensure that motorists can get to their destination.”

This winter, CDOT will have 245 employees battling winter conditions in the Denver metro area who will work in shifts from 5 a.m. to 5 p.m. and 5 p.m. to 5 a.m. in order to keep 3,850 lane miles of highway clear of snow and ice. The maintenance crews will use a variety of equipment to apply solid and liquid de-icers. In all, 121 pieces of equipment will be used including 100 snow plows that apply liquid and/or solid de-icers, three 6,000-gallon tankers that apply liquid de-icers and 18 brooms to sweep up or pick up material after a storm.

To help crews combat snow and ice on bridges, overpasses and tunnels, three automatic de-icing systems will be operational this winter in the following high traffic volume locations:

• Eastbound I-270 to Eastbound I-76
• Southbound I-25 to Northbound I-225
• Southbound I-225 to Southbound I-25

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.

“Bridges and overpasses tend to freeze first and with the help of these three systems, we can cover more highway and attack other problem areas,” said CDOT Deputy Maintenance Supervisor Greg Hayes.  “This is a great tool to have in our winter maintenance arsenal and it will greatly benefit our crews during snow events.”

The automatic de-icing systems are not the only technology tool that Denver area maintenance crews rely on.  In fact, there are 20 snowplows in the Denver metro area 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.

Like in past years, 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.

CDOT will also use APEX, which is magnesium chloride-based product used above -4 degrees Fahrenheit.  Due to a lower freezing point, it can serve as regular and cold-temperature magnesium chloride and is the most efficient product for the automatic bridge de-icing systems as crews do not have to change products during a snow event when the temperature drops.

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.

Last year, CDOT used approximately 1.1 million gallons of liquid de-icer and over 17,000 tons of solid de-icers in the Denver metro area while plowing, sanding and/or de-icing nearly 753,700 miles of road. CDOT spent approximately $6.8 million in the Denver area between July 2009 and June 2010, which was up 32% from July 2008 through June 2009 when CDOT spent $4.7 million.

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 www.cotrip.org or by calling 511 anywhere in Colorado. Current road and weather conditions are available 24 hours a day, seven days a week via the Web and phone.

You can also sign up for e-mail and text message alerts by visiting www.coloradodot.info and clicking on the cell phone icon in the upper right corner under the search function.  You can then subscribe to any of the lists free of charge (standard text message rates do apply).

Here are a few winter driving tips to remember:

• Be sure to carry plenty of windshield wiper fluid 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 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, matches and nonperishable food in your car.
• Make sure your tires have good tread.

**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 procession 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 to 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.