The extreme weather that struck large parts of the country this winter has highlighted the inadequacies of Canada's aging infrastructure.

In Toronto, city crews worked to fill thousands of potholes on Monday that opened up during the weekend when temperatures rose to 7 C.

The sudden spike in the mercury came after a week of frigid temperatures that reached as low as – 40 C with the wind chill.

"We've seen an increase of a little more than about 50 per cent," City of Toronto Road Operations Manager Hector Moreno said. "We've got about 4,000 potholes right now from year-to-date compared to 1,500 that we did last year."

The sudden thaw comes just a few weeks after a major ice storm hit southern Ontario, leaving hundreds of thousands of residents without power in late December and early January.

Toronto city council voted unanimously on Monday to ask the province and Ottawa to help with the estimated $171 million in cleanup costs from the ice storm, as well as a July storm that flooded major parts of the city. The city is seeking $57 million from both the province and the federal government.

Toronto Hydro spokesperson Tanya Bruckmueller told CTV News that moving forward, Toronto Hydro will look at updating the city's electrical grid.

"A third of our grid is past its lifespan, however it still performs relatively well considering," Bruckmueller said. "In the downtown core we have equipment that could be 60 to 70 years old."

That upgrade may include a $15-billion plan to bury power lines so they're not susceptible to storms, she said.

Meanwhile in Montreal, a major highway was closed for hours Monday afternoon after a chunk of concrete fell from an overpass.

A piece of concrete fell from the Henri Bourassa overpass onto Highway 40, striking a vehicle, police said. Several other vehicles also suffered damage after they drove over crumbling concrete pieces on the road.

Saeed Mirza, a McGill University professor of civil engineering, said the situation in Montreal has become "dire."

Mirza said that Montreal's problems with potholes, crumbling bridges and aging sewer pipes are being seen right across the country.

He said infrastructure investment is needed in order to maintain Canada's competitiveness.

"If we don't do it today, I think we will become a developing country with our infrastructure deteriorated to such an extent that it will influence our productivity and international competitiveness," he said.

Last June, Mirza projected that there are $1 trillion worth of repairs and improvements that need to be done across the country.

Brock Carlton, the CEO of the Federation of Canadian Municipalities, said that federal funding for infrastructure has been steadily drying up since its peak in the 1960s.

"It's near a crisis with roads crumbling and water systems struggling to keep up with growing demand in urban areas," he said. "These extreme weather events are a classic illustration that just put a spotlight on the general decay of municipal infrastructure in this country."

In recent years, there have been calls for a national infrastructure strategy, where all levels of government would work together to identify, pay for and fix key infrastructure areas before the next natural disaster hits.

With a report by CTV National News' Toronto Bureau Reporter Peter Akman