Montreal's mayor says the crumbling infrastructure in his city serves as an ominous warning for the entire country of what could happen unless urban centres get more funding.

Gérald Tremblay held a news conference Tuesday near a partly collapsed tunnel to argue that federal and provincial governments need to invest more political capital in cities.

He derided recent funding as a drop in the bucket compared to the needs of cities — estimated by some economists at $120 billion.

Tremblay said his administration has been forced to take unpopular measures with fees and parking meters, and he urged his counterparts at the federal and provincial levels to show similar courage.

He cited two possible examples: provincial toll booths and an increase in the federal gas tax.

"Sometimes it takes a crisis to make decision-makers move faster," Tremblay said. "But it's not just a Montreal problem.

"When I talk to my colleagues in other big Canadian cities it's the same issue — we have a $120-billion hole...

"Eighty per cent of people in Canada live in cities. We need to recognize their needs better, on a financial level."

Bad year for Montreal roads

Montrealers have reached a boiling point in the wake of road shutdowns, collapsing concrete, and warnings of potential danger to major existing infrastructure.

The city already deals with monster traffic jams at odd hours, and there are fears the problem may get worse.

The Quebec government has taken much of the heat during Montrealers' summer of discontent.

Some observers call Montreal's problems a special case — the result of too much road salt, too little inspection, shoddy workmanship and winters far colder than Toronto's.

The provincial government has sought to divert the blame, in part, to past administrations that either ignored infrastructure or laid off inspectors because of fiscal constraints.

Quebec also defended itself amid reports Tuesday that an engineering study three years ago accurately warned about the potential ceiling collapse above the Ville-Marie Expressway.

A 2008 engineering report warned the tunnel's deteriorating condition was in a "critical" state and had become dangerous to users.

But Transport Minister Sam Hamad said the province had already conducted the necessary safety inspections and maintenance work recommended in that report.

He suggested Sunday's incident, where a 25-ton chunk of concrete smashed onto the expressway, was unrelated.

Hamad said it was work at a nearby construction site, and not long-term damage, that may have destabilized the tunnel's ceiling.

Still, Hamad admitted more work is needed on the provincial road infrastructure.

"It's clear that over the last 20 years there was not enough investment," he told reporters Tuesday.

"Citizens are asking, 'What's going on with our infrastructure?' And they're right."

'Citizens are feeling insecure' says mayor

The concrete cave-in comes at a time when Montreal's aging, decaying road network has forced the closure of several sections of major overpasses and bridges.

The state of the city's road network – which has caused monstrous traffic jams for years and, now, safety concerns – has long been a local frustration.

The heightened tension was palpable at Hamad's news conference Tuesday when one of his staff members got into a shoving and shouting match with reporters during a testy question-and-answer session.

That came after a column in a prominent newspaper Tuesday that included a swear word in its headline, in reference to the transport minister.

Hamad says his department will be transparent and release all engineering reports on the tunnel to the public.

The mayor acknowledged the public frustration.

"When you look at citizens' comments, when you read the newspapers, citizens are feeling insecure — they're worried," Tremblay said.

"And when citizens are worried, that has consequences on economic prosperity."