Transport Quebec has banned double tractor-trailers from about 135 highway bridges and overpasses until inspectors finish tests to determine their safety.

Bridges and overpasses scheduled for inspection include: In Montreal: Highway 520 south at the Dorval airport split. Cote-Vertu Boulevard and Highway 13 junction. Highway 25 and Tellier Street junction. Highway 138 at Monette Street. Highway 720 at Bleury Street. In Laval: Highway 341 and Highway 40 junction. In Quebec City: Highway 40 at Rivière des Pommes junction. Highway 40 at Labelle Street. Highway 40 at Jean-Gauvin Road. Highway 40 at Rivière Beauport. In the Eastern Townships: Highway 10 and Route 122 junction. Highway 55 at the CP and Venise Road junction. In the Chateauguay Valley: Highway 10 at Ruisseau Barré. Highway 10 and Rivière Birère-Lafrance. In the Outaouais: Highway 301 and the Outaouais River. Highway 366 at the Gauvreau Lake exit. Highway 117 at the Coupal Lake exit.

The provincial Transportation Department also said it was suspending all special permits for heavy trucks on those structures, because they were built in a similar fashion to the Concorde overpass in Laval, which collapsed in late 2006 killing five people.

The highway structures will be examined for any weaknesses or deterioration, and will be reinforced if necessary, transport officials said as they released the list moments after the Johnson Commission wrapped up its hearings into the Concorde overpass collapse.

But there is no immediate danger, and drivers of regular vehicles shouldn't be concerned about using the roads while the inspections are underway, stressed Jacques Gagnon, a regional director with Transport Quebec.

"It must be clear for all, they can travel on the network without any fears," he said.

The inspections may require repair work including steel reinforcement, he added. "It’s just to check some specific aspects of the design, that is particular to that type of structure."

Commercial truck drivers will have to take detours to avoid the 135 bridges and overpasses — but Transport Quebec will offer alternate routes.

The special inspections will start in the fall.

End of hearings at Johnson Commission

The truck ban and additional inspections were announced as former Quebec premier Pierre Marc Johnson concluded hearings at the commission investigating the Concorde overpass collapse.

The commission has heard from various expert witnesses who have offered different theories on why the overpass spanning Highway 19 north of Montreal collapsed last September.

Some engineers said it was a flawed design, others suggested there were shortcuts taken when the structure was first built — and some witnesses said repair work done 15 years ago on the overpass weakened the concrete and allowed it to deteriorate.

Demolition crews finish the destruction and removal of the Concordia overpass crossing Highway 19 in Laval, north of Montreal, on September 7, 2006.
(Peter McCabe/Canadian Press)

Johnson said the challenge now is to sort through all the testimony and evidence and arrive at concrete conclusions.

"It’s up to us to formulate a consensus, if we can call it that," he said Thursday afternoon.

"I know [transport officials] are deploying resources in a context that’s not always easy," he said. "I’m convinced that Quebec citizens are counting on those efforts."

The list of 135 structures requiring inspection was spurred by a rare warning from Johnson last spring during the first phase of the overpass commission hearings.

Johnson said there were dozens of highway bridges and overpasses across the province that were risky because they were built using the same design as the Concorde span.

The commission will reconvene again in August for final arguments, then will spend the next two months drafting their report.

The Johnson Commission has cost $3.5 million.

With files from the Canadian Press