A salt-sand combo
While we never know what Winter will throw at us, provincial, municipal and county road maintenance crews know in advance how to respond to storms.
There are some basic strategies, as outlined by the Ontario Ministry of Transportation.
Spreading of salt begins within 30 minutes after the start of a winter storm, helping to melt snow and ice, preventing it from sticking to the highway. It also makes plowing more effective.
Sand is used to provide traction on slippery surfaces, especially when it is too cold for salt to be effective. It may be used at higher temperatures if traction is needed immediately, particularly on hills, curves, bridges and intersections, and on snow-packed highways.
Both are spread on the highway using a truck that carries the material in a hopper. On two-lane highways salt is directed through a chute and generally placed in a narrow strip along the centre of the highway. On multi-lane highways, spinners are used to spread salt across one or more lanes at a time.
Salt is less effective at temperatures below -12° C, especially if there is no sunlight, which means bare pavement can be difficult to achieve in extremely low temperatures.
There's no “one size fits all” response to winter storms. The winter maintenance equipment and materials used depends on weather conditions (temperature, precipitation type, duration and intensity, cloudiness, humidity, wind), highway conditions and amount of traffic. That's why maintenance crews continually monitor weather and highway conditions. They patrol the highways and use advanced systems for predicting and monitoring weather and highway conditions so they can prepare the right equipment and materials before a storm, adjust their activities as conditions change.
Anti-icing liquid can be sprayed on a highway before a storm to prevent snow and ice from forming and sticking to the highway. It can be placed along a section of highway or at specific locations prone to icing, such as bridge decks. Anti-icing liquid is only applied at specific temperatures and weather conditions.
Once the storm hits, snow plows, combination trucks and tow-plows are used to clear the snow and restore the highway to bare pavement conditions. A standard snow plow truck has a blade mounted on the front and may also have a side blade or “wing.” A combination truck has a spreader mounted on a standard snow plow truck and is capable of both plowing and spreading. A towplow is a regular plow blade mounted on a trailer and pulled by a combination truck. The trailer is moved over to the right to clear the next lane.
Ontario 511 is an Ontario Ministry of Transportation telephone service that provides the public with voice-activated, hands-free information on provincial highways. Just dial 511.
A QUESTION OF DEGREES: Road salt becomes less effective below -12 degrees; sand is used below -18 degrees to improve traction.