Left: The city of Surrey, British Columbia, teaches drivers how to inspect a plow before taking it out on the road. Below: The city of Port Coquitlam, British Columbia, preps roads with pre-wetted salt before a snow or ice event. Photos: Coastal Training Consultants Ltd.
Part of the calibration process involves educating operators to travel at the appropriate speed. This can be a challenge, since operators are often pressured to get the job done within a timeframe and under difficult circumstances.
For instance, if salt is spread down the crown of the roadway at 15 mph, the salt stays right where it was placed: 3 to 6 feet wide on the crown. But when the vehicle accelerates to 20 mph, approximately 33% of the material is lost because it either lands on the road shoulder, on the grass, or in the curb. At 25 mph, material loss is as high as 66%, as the material pattern is so wide that the traffic crushes up the salt and blows it off of the roadway.
About 1 pound of salt will melt about 43 pounds of ice at just below freezing. The colder the temperature, the less effective salt becomes, and adding material will not help.
If material is placed too sparsely on a snow- or ice-covered road, re-freezing occurs. If that salt is spread too widely on the roadway, the snow and ice will melt somewhat, but may refreeze or create a watery surface on the icy road, which is considerably more dangerous than just ice on the road.Getting Drivers Ready
No equipment, no material, and no strategy will be effective if the operator doesn't have the knowledge and skill to make it all come together.
Annual snow and ice control meetings are beneficial to prepare crews for the season. Operators can be brought up to date in all areas of the snow and ice control plan for that year. New techniques, products, and equipment can be discussed.
Operators can get into the “snow and ice control mode” through dry runs with the equipment on the routes. This allows them to see any changes to the routes and hazards that exist, such as bulbing of curbs, traffic islands, left turn lanes, traffic light changes, and priority route changes. New operators can be trained in getting to know routes and their time-related hazards, such as school zones and commercial districts' rush hours.
Driver selection also is important. Snow and ice control operators must be good truck drivers, because inexperienced drivers can be intimidated by the snow and ice control task.When Doing Nothing Is Best
With all the information available and with a good plan in place, there is also the strategy of using basic common sense.
For example, one city put dry rock salt on a roadway where the temperature was cool, about 23° F. But the sun was bright and the roadway was very dry. The salt was hygroscopic and drew moisture from the pavement, refroze, and created black ice. Sand had to be applied in generous amounts to counter the effect of the ice created by the rock salt.
A better course of action may have been to do nothing, since the air was dry and there was no forecast of any moisture.
— Wasstrom is a long-time driver and equipment operator trainer with Coastal Training Consultants Ltd., based in Coquitlam, British Columbia.Back to basics
Keep it simple when selecting products and techniques.
Get all the facts before using any new product or technique for your community's snow and ice control. Examine each option for:
- General effectiveness
- Impact on the environment
- Operator ease.
An additional tip: find another public works team in an area that is similar in climate and geography to your own. Compare information and ideas. If a community has had positive experience with a product and a strategy and can provide feedback, this can be very helpful.