Protecting a National Forest with New Snow Removal Methods
The California Department of Transportation adopted new technology to give the forest road around Mount Shasta special treatment.
The Challenge
When winter weather strikes, the California Department of Transportation (DOT) needs to pay extra attention to a 3-km (2-mi) stretch of Interstate 5. Located along the base of 4,267-m (14,000-ft) Mount Shasta, this heavily traveled roadway must be kept as close to bare as possible while preserving the environment.
"The National Forest location demands special treatment when abrasives and chemicals are used during snow removal and ice-control operations," according to Kathy Coots, District 2 maintenance supervisor for California DOT.
Developing a Strategy
This situation led California DOT to install a road weather information system (RWIS) evaluated and enhanced under the Strategic Highway Research Program (SHRP). The advance information on approaching weather conditions provided by the RWIS would be combined with a test of anti-icing materials and methods as part of a Federal Highway Administration (FHWA) evaluation.
The goal was to be able to know when to apply anti-icing chemicals in advance of a storm in order to allow break-up of snow pack sooner and more easily. The California DOT also wanted to find an anti-icing material that was less corrosive to private vehicles and to their own snow removal equipment.
Putting the Strategy to the Test
Based on predictions from the RWIS, California DOT would decide when to apply deicing chemicals. If a significant storm was predicted, chemicals would be applied before the pavement would reach freezing temperatures. If the forecast was for a possible winter storm, the deicing chemicals would not be applied until the RWIS indicated pavement temperatures of 1 ºC (33 ºF).
What They Learned
Liquid anti-icing chemicals were found not only to have less of an abrasive effect on the environment, but also demonstrated a longer residual effect, reducing the amount of material used.
Compared to solid chemicals, the liquid anti-icing chemicals could also be applied further in advance of a storm, providing a more uniform application, and breaking up the packed snow sooner and more evenly. California DOT was also pleased to see that its application involved less time, staff, and equipment.
Differences were also noted in advantages of the storage and handling of liquid anti-icing chemicals versus salt. "Unlike liquid chemicals, salt is very corrosive to storage facilities and tends to collect moisture, which can impede loading," Coots says.
The Benefits
The combination of RWIS information and the new anti-icing techniques provides
- A safer roadway.
- Less abrasive anti-icing treatments that are more protective of the environment.
- Reduced costs as a result of requiring less staff, equipment, and materials.
