Toronto’s pothole patching blitz swings into high gear today, and none too soon, judging by the weather.

With double-digit temperatures coming this week, melting snowbanks will pour salty water over the curb and into the potholes, where the freeze-thaw process will make them bigger and more plentiful.

When temperatures drop below zero at night, water in potholes freezes and expands, loosening the pavement around the edges. And when it warms up during the day, passing traffic causes the pavement to crumble, increasing their size.

As of Monday, transportation services is doubling down on the number of workers that have been filling potholes, with at least 32 crews deployed this week, said Hector Moreno, a city road operations manager.

So far this winter, 31,000 potholes have been filled at a cost of $740,000, a far cry from the 66,000 filled for the same period last winter, at a cost of $1.2 million, said Moreno.

The difference is the freeze-thaw cycles; there were 40 last winter, compared with just 10 for the same period this year, he said.

“There was no thaw in February, just freeze,” said Moreno, noting that this winter is much colder, but the 2013-14 winter began at the end of November and was much longer in duration.

To put it in perspective, the city filled 385,000 potholes last winter, at a cost of $5.8 million, far more than the previous high of 290,000 in 2008, he said.

The five-year average the city uses as a baseline is 230,000, with a cost of $3.5 million.

But the worst is still ahead. The record cold in February pushed the frost line more than two metres below ground, when it doesn’t go down much more than one metre in an average winter, he said.

“So you’re going to see a lot more cracks and bumps in the road as the frost comes out and pushes up. It puts a lot of pressure on the pavement structure and is why we have to do so much maintenance in the spring.”

Transportation services is also sending out crews to clear catch basins of ice and snow, said Moreno, adding that homeowners can help prevent flooding by clearing any grates in the curb near their property.

The patching blitz will continue into April, when the number of potholes usually peaks. Potholes can be reported by calling 311 or using the city’s website, toronto.ca.

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The city tries to keep its commitment to fill all reported potholes within five days, but with the worst of pothole season still ahead, it may sometimes miss its own mark.