Anti-icing involves placing a layer of brine solution on the road surface before a winter storm begins in order to prevent snow and ice from bonding to the road.
De-icing uses pre-wetted rock salt to break the bond after snow has frozen to the road surface.
Objectives for our anti-icing and de-icing strategy
- Ensure adequate winter road safety
- Ensure material is being applied effectively without unduly affecting the environment or our road infrastructure.
Applying salt or brine to icy roads and walkways lowers the freezing point of the water and prevents falling snow or rain from being able to freeze. Road salts are by their nature corrosive and will require residents to wash their cars and driveways in order to reduce exposure, but they are essential to maintain reasonable road surface conditions during the winter months.
On Whoop-up Drive, our Transportation Operations Unit uses a mix of 90 per cent salt with 10 per cent sand and pre-wet (a calcium chloride brine solution). This mix reduces bounce, and studies indicate 30 per cent more material remains in the travel lane after it's applied. Our objective is to achieve a bare, wet road surface for vehicles when temperatures are between 0 degrees Celsius and -20 degrees Celsius. Once the temperatures drop below -20 degrees Celsius, salt becomes ineffective, and we change to a higher ratio of sand to create friction.