Seven myths about snow removal
Did you know about 190 cm of snow and 175 mm of rain falls on Montréal each winter? Snow and ice removal operations are essential to urban mobility in winter, yet there’s a lot most people don’t know about it. Check out these seven myths about snow removal in Montréal.
1 - Snow removal on major streets occurs at random.
After each snowfall, more than 10,000 km of streets and sidewalks have to be cleared of snow. This is the equivalent of the distance between Montréal and Beijing, or 40 times the distance between Montréal and Québec City. With all this area to cover, snow removal is prioritized as follows:
1: Major streets and reserved lanes (Rue Sherbrooke, Boulevard Pie-IX)
2: Collector streets (Rue Beaubien, Rue Saint-Hubert)
3: Residential streets (Avenue Des Érables, 5e Avenue)
2 - Bike paths are cleared of snow before sidewalks.
Bike paths are cleared of snow at the same time as sidewalks and streets. You may have the impression they are plowed earlier for three reasons:
- There are fewer kilometres of bike paths than sidewalks.
So, snow removal from bike paths takes less time.
- There are fewer obstacles to avoid on bike paths.
The crawlers that clear sidewalks must navigate around garbage bags, bins, trees, flower beds, improperly parked cars and sometimes even piles of snow left on the sidewalk by residents. Bike paths are generally free of obstacles, so clearing them goes faster.
- Asphalt paths are warmer than concrete sidewalks.
Bicycle paths are generally paved. Asphalt stores heat from the sun, which helps melt snow. Sidewalks are usually made of concrete, a material that stays cold and keeps snow or ice in place.
3 - When there is a thaw, we should let the snow melt instead of removing it.
Melting snow with the help of the sun can be advantageous, but it’s also risky. If the temperature drops, the wet snow freezes into chunks or patches of ice. Sidewalks become icy, snowbanks turn into ice blocks and sewer grates become blocked. In such scenarios, it can be much more complex, time-consuming and sometimes nearly impossible to correct the situation.
If all the snow was left on the ground, with all the trampling and thaw-refreeze cycles, by the end of the winter we would have a layer of snow and ice about 1.5 m deep.
4 - If more salt was spread on sidewalks, they would be less icy.
Salt “melts” ice relatively well when the outside temperature is between 0⁰C and -15⁰C. When it gets colder, the salt loses its effectiveness. This is why gravel is used as an abrasive to make surfaces less slippery. In fact, mixtures of salt and gravel are often used on city streets and sidewalks. This provides the advantages of both products. However, neither is magic. In addition, they have an impact on the environment. Salt is corrosive and can damage various materials (clothing, metals, underground pipes, etc.) as well as plants. The gravel accumulates on the ground: it must be collected and decontaminated in the spring.
Did you know that Montréal uses an average of 150,000 tons of salt each winter?
5 - The city often waits too long before starting to clear snow.
Snow removal is a matter of strategy. To decide what strategy to deploy and when to start, you need to know when the precipitation starts, how fast it falls and whether it will turn into freezing rain.
Here are some examples:
- When the snow falls quickly, it can seem as if the snowplows have not been there. They may come early in the storm, but the snow that continues to fall erases all trace of their passage. They have to finish their routes before clearing the same location a second time.
- When freezing rain follows a snowfall, it is best to leave a thin layer of snow on the ground. This absorbs some of the rain, which makes it easier to clear away, rather than trying to melt ice that has fallen on a completely clear sidewalk.
6 - Some trucks dump snow directly into the river.
Each winter, snow removal crews collect, transport and dispose of an average of 12 million m3 of snow, the equivalent of 10 Olympic stadiums full of snow. This snow can take two paths:
- Most of it is stored on huge plots of land where it forms mountains several tens of metres high. This snow will take several months to melt. Any debris that remains (trash buried in the snow at the time of removal) will be disposed of in the garbage.
- A quarter of the snow is dumped into one of the sewer chutes: huge holes that open into underground pipes. The heat of the wastewater helps melt the snow before it arrives at the treatment plant, which treats all the water before discharging it into the river.
7 - Towing is a good source of revenue for the city.
Every winter, an average of 50,000 cars are towed away because their owners violated the snow removal parking ban. A single tow delays the removal convoy by about 10 minutes.
When you add up the cost of the tow truck and the salaries of the employees who have to stop loading and wait for the cars to be moved, the tows are a loss for the municipal government and all taxpayers.