Anti-Icing Techniques Key to Safer Roads
Missouri is using anti-icing methods to keep roads clearer when winter storms hit.
The Challenge
Icy roadways present a hazard for Missouri motorists and a challenge for the State's road departments. The Missouri Department of Transportation (DOT) recognized that keeping road surfaces safe during the winter months often depends on the proper application of chemicals to prevent ice from forming and bonding to the pavement. But what method would offer optimum performance with a minimum amount of chemicals?
Developing a Strategy
In an effort to answer that question, Missouri adopted anti-icing techniques developed by the Strategic Highway Research Program (SHRP). Missouri DOT determined it could improve road conditions and cut its chemical use in half by prewetting sodium chloride with 22.7 l (6 gal) of liquid calcium chloride per ton.
Putting the Strategy to the Test
The new anti-icing strategy was implemented in eight counties in and around Kansas City.
What They Learned
"The anti-icing technique met our expectations in clearing roads faster," said Ivan Corp, district maintenance engineer for Missouri DOT.
Missouri DOT discovered that sodium chloride brine could be an effective and less costly alternative to liquid calcium chloride. The brine is easy to make and costs 10 times less to produce than calcium chloride. Sodium chloride brine also outperformed liquid calcium chloride, keeping the pavement clear of ice and snow for up to 2 hours longer.
Equipment limitations restricted the number of pavements that could be treated with salt brine during the winter of 1995-96. Next winter, however, all eight counties in the district will have the necessary equipment.
The Benefits
- The anti-icing technique resulted in clearer pavements, thus improving motorist safety.
- The environment was less affected, as fewer chemicals were used.
