I can understand your concern that there was de-icing material applied and that the forecast had not indicated any snow or freezing rain.  With the type of temperatures that we have been receiving lately, the City’s Roads and Parks Operations staff monitor conditions and apply what is commonly known by municipalities with more sophisticated means of winter control as a direct liquid application.  In late fall and early spring the temperature of the road can dip below the dew point temperature (point that moisture can no longer be held in air and it is deposited on various surfaces including roads) and when this happens frost or black ice is formed on the pavement resulting in icy road conditions.   The City owns 3 weather stations located in various areas across the city that monitor air, road and dew point temperatures and can predict when frost or black ice will occur.  The City forecast on November 10^th and 11^th is shown below and indicates that frost/black ice would be present in the early morning hours of November 11^th (pink shaded area).

Roads and Parks Operations staff take a pro-active approach to prevent black ice from forming and dispatch direct liquid application equipment to treat roads with salt brine during normal working hours to minimize overtime when possible.  The water may evaporate but the salt residue remains on the road ready to work.  Responding to icy conditions is a requirement of the municipality under the Municipal Act (Minimum Maintenance Standards for Municipal Highways) and is carried out for public safety reasons.  If an accident should occur and the City is found liable, the payout costs can exceed the City’s entire annual winter maintenance budget. 

The liquid material placed this time of year is salt brine that is manufactured by City staff at our Operations Center on Ferndale Drive at between 6 and 9 cents per liter.  Direct liquid application uses less salt and is much cheaper than spreading granular salt as well as being much preferred for the environment.  As Councillor Brassard has mentioned, the City does use a sugar beet derivative when the temperature dips below about -12 degrees centigrade, as salt become less effective at these temperatures. 

Please contact me if you would like to discuss in more detail. 

Regards,