From last week’s bitter winds of -40°C to the balmy (in comparison) 5°C temperatures Montreal will experience in the coming days, the weather this winter has been nothing short of intense and erratic.
But these wild weather-swings aren’t just a problem for us now, in Winter. Come summer, we can expect an influx of potholes due to the stark changes in temperature, according to the Ministry of Transport.
A cold wave followed by mild weather is damaging to roadway conditions, a lead engineer at the Ministry of Transport’s “pavement laboratory” told La Presse, which could create an increased number of potholes once the warmer weather hits.
Yes, there is a “pavement laboratory” where experts track the state of streets using “road-weather” stations that can measure the temperature of the ground up to 3 meters deep. Using these devices, engineers can track how deeply roads are frosted over.
This winter we’re already experiencing a deep freeze on roads. Frost is recorded to reach 1.12m below the ground, in comparison to the average of 70cm to 80cm from past years.
Frost itself isn’t a problem. The issue arises when warm temperatures follow a deep freeze (like we’ll experience in the next couple of days) which causes the top layer of the street to unfreeze while deeper levels remain frozen.
Thawing on the surface but staying frozen towards the bottom creates a bunch of trapped water in the road, which accumulates and damages the upper levels of asphalt. Roads are damaged five to eight times faster under these conditions.
Somewhat fortunately, Montreal’s roads being frozen 40% more than past years isn’t a major problem, yet. When the frost descends below 1.5m is when we really need to be worried, which could still happen, since we still have January and February to get through before winter is over.
And if another warm spell follows a deep freeze, the same process of road-damage will occur.
A slew of new potholes is a reality during every spring and summer in Montreal. But the recent (and potentially, future) weather patterns may make it far worse in 2018.