The Turcot Interchange and the Bonaventure Expressway were thrown up amid Montreal's rush to transform itself into a modern city.

Now they're coming down amid another rush to modernize and amid a different vision of what the modern city looks like.

This weekend the Saint-Jacques overpass began to be demolished, with the Turcot proper soon to follow. And the Bonaventure is currently being turned into rubble.

A true metropolis

Both structures were opened in the run-up to Expo 67, Montreal's debutante ball. Almost by sheer force of will, Mayor Jean Drapeau was intent on ensuring the city had the infrastructure required of a true metropolis.

Urban planning at the time was in thrall of concrete and the car. In the years before Expo, close to half the city's budget was spent on road improvements.

The zeitgeist dictated a modern city didn't preserve its past, it razed it to the ground to make way for the future.

As many as 850 homes were demolished in order to build the Turcot and Ville Marie Autoroute. Opposition to the projects was steamrolled, almost literally.

More than roads

But when it opened the Turcot wasn't just a road, it was an aesthetic experience. Drivers soared one-hundred feet into the air, and at night their Falcons and Bonnevilles were bathed in the fluorescent lights built into the Turcot's boundary walls.

"It felt like you were in a spaceship," said Pieter Sijpkes, a professor of architecture at McGill University who had just moved to Montreal from the Netherlands when the Turcot opened.

"It was really quite amazing. There was something sexy about it."

Projet Bonaventure after its makeover. (City of Montreal)

Decay sets in

The Turcot's fluorescent lights, however, had to be ripped out almost immediately after they were installed. Their aluminum casings were eaten away by acid created by the interaction with salt water and concrete.

It was a harbinger of what awaited the grand structures meant to define Montreal's modernity. In the rush to built the Turcot, the Bonaventure and even the Champlain Bridge, little thought was given to managing salt-water runoff.

This, says Sijpkes, was a "deadly sin ... All these structures were destroyed by salt water."

All three have aged badly, and help make the modernism of the 1960s appear quaint at best, and at worst, a destructive bout of utopian thinking.

Grey to green

The city is now once again in the throes of a wave of construction that will define its urban texture for another generation or two.

This one, though, takes green rather than concrete-grey as its imperative.

The Bonaventure is being replaced with an "urban boulevard" — inbound and outbound lanes will be separated by an expanse of greenspace. For its part, the Turcot will be lowered and landscaped on either side.

Perhaps most indicative of the new mindset guiding Montreal's urban planning is the proposed light-rail system that will connect parts of downtown with the West Island and the South Shore.

This generation's legacy project, in other words, won't be a road network but a mass transit system.

One modernism for another?

Designers included the rail corridor in plans for the new Turcot Interchange thinking it would serve a planned airport shuttle train. (Radio-Canada)

One of the oft-criticized aspects of modernism as an urban planning ethos was its authoritarian character. Solutions are imposed from above, with little regard for realities on the ground.

Similar concerns have been voiced about some of the recent construction projects.

Quebec's Transport Ministry ignored proposals to restore the existing Turcot and create an urban park beneath it. Ignored too were concerns of residents worried about increased traffic to the area.

And when work crews discovered remnants of a 18th-century village, it was bulldozed rather than hold up the construction schedule.

"The Minister de Transport de Quebec is a very insular outfit that hardly communicates with the public and really wants to do its own thing," Sijpkes said. "And they make terrible mistakes because there is no real public input."

The lure of progress can make us impatient. But rushing into the future only ensures few lessons will be learned from the past.