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Still, the main cause of potholes lies not with weather or thrifty politicians, but rather with the composition of the asphalt that makes up the streets, according to an iconoclastic Dutchman (the best kind), Simon Hesp.

Prof. Hesp, who teaches chemical engineering at Queen’s University in Kingston, says paving companies err when they mix used motor oil into new asphalt. This yields brittle pavement that is prone to crack. Our roads, he says, are designed to fail.

“The industry doesn’t want to listen to this because they want to come back early and often and there is a lot of money to be made in putting engine oil into asphalt cement,” he says.

In a typical year, crews at the city fill in 170,000 to 180,000 potholes. But 2014 is not a typical year. Peter Noehammer, director of transportation at the City of Toronto, says his men are exhausted.

“Because the winter has been more severe they have been busy in winter as well,” he says. “Then they jump into pothole repair. We’ve had to put in a lot more hours this year and work Saturdays.”

Extreme cold stresses asphalt, causing cracks. Water seeps into cracks and freezes, creating a kind of lens of ice. That ice melts in spring, leaving a void. Drive over that void and presto: a pothole.

To repair these craters, every day the city sends out between 30 and 40 crews. Each two-person crew drives a pickup truck pulling a “hot box,” carrying asphalt they pick up from an asphalt plant. “They are starting to get tired,” says Mr. Noehammer. “As lucrative as overtime can be, they are running out of energy.”