When do we plow?
Triggers and targets are guided by the Integrated and Accessible Transportation Policy - 2015 (pdf) . During a typical snowfall, here’s when we plow roads:
|Purple||Hills, bridges, overpasses, high hazard locations and hospital access.||Plow within 8 hours of 5 cm accumulation.|
|Red||Major arterial roads||Plow within 72 hours of 8 cm accumulation.|
|Downtown roads||Plow and remove within 4 days of 10 cm snow pack
(30-40 cm accumulated snowfall).
Plowing happens overnight (7 p.m. to 7 a.m.)
|Green||Collectors, Transit Routes, and
residential streets adjacent to schools
|Plow and remove within 15 days of a 10 cm snow pack (30-40 cm accumulated snowfall).|
|Grey||Residential streets||Plow within 15 days of a 10 cm
snow pack (30-40 cm accumulated
snowfall); plowed to a 5 cm snow pack
and windrows on both sides of the street.
|Orange||Industrial and commercial areas||Plow within 5 days of a 15 cm snow pack,
plowing can start prior to the 15 cm trigger
when it makes operational sense to do so.
We also clear snow for sidewalks, trails and transit stops:
|Sidewalks||Within 3 days of a snow event.|
|Trails||5 cm snow pack in select Waskasoo Park trails|
|Transit stops||Within 10 days of a snow event.|
In the event of exceptional snowfall events, operations adjustments may need to be made to these triggers, and routes may need to be prioritized.
Sanding is ongoing throughout the winter and the frequency in which we sand depends on weather and road conditions. After frost, freezing rain, or snow, we sand hills, bridges, overpasses, high hazard locations, hospital accesses and arterial routes first. Green Routes and Orange Routes are sanded next.
The type of traction control we use throughout the winter is dependent on the road temperatures:
- -7°C or warmer – sand is “spiked” with 25% dry salt or salt brine is manufacture in-house by mixing water and sodium chloride to create an optimum solution of 23.3% salt content by weight. This is the concentration at which salt brine has the lowest freezing point.
- -12°C or warmer – salt brine is used to pre-wet roads to help sand stick to the roads. This method can only be used when road temperatures are -12°C or warmer.
- -12°C and colder – straight sand is used as salt is no longer effective below -18°C.
When it becomes extremely cold and the road is bare, sand is pushed off the roads by high volumes of traffic and does not stick.
With the dynamic weather conditions and fluctuating temperatures we receive here in Red Deer, Public Works is constantly monitoring road conditions with these factors in mind. Adjustments to the sand/salt mixtures are made as necessary. To request sanding, please call Public Works at 403-342-8238 at any time.