Premier Jean Charest is promising a massive investment in Quebec's aging roads, bridges and overpasses following the chaotic closure of Montreal's downtown core on the weekend caused by the discovery of a crack in a tunnel under de Maisonneuve Boulevard.

But, Charest said Tuesday, his government will deal with problems in the province's infrastructure on a case-by-case basis.

After the collapse of the de la Concorde overpass in Laval killed five people last September, the government ordered a massive inspection of Quebec roads.

Charest said that approach can't be applied to the problems in Montreal, which also include extensive repairs being made on the downtown Ville-Marie Expressway.

"We'll do it on the expertise, based on the expertise that our officials will offer us. In other words, we don't just want to take a gunshot approach, and do everything. I think we want to make sure we take an approach based on the evaluations we have," he said.

However, Charest said, if there are security risks, the government will act without consideration for cost. 

The premier pointed out that his last budget included $30 billion dedicated to infrastructure projects over the next five years.

He said previous governments did not spend enough on maintaining and developing the province's roads, sewers and bridges.

A city of Montreal spokeswoman said Tuesday the one-block stretch of road on downtown's de Maisonneuve Boulevard remains closed to traffic indefinitely, and no dollar figure has been assigned to the necessary repair work.

Meanwhile many lanes are closed as work continues on Montreal's Ville-Marie Expressway, which is used by millions of commuters every day.

With files from the Canadian Press