WHEN MONTREAL’S TURCOT Interchange opened in 1966, no one had seen anything quite like it. Floating one hundred pillared feet above the ground, its concrete spans swirled and swooped through the air, finally coming together in a knot of jaw-dropping proportions. It comprised over seven kilometres of road and spanned an area of seventeen acres. Underneath its four levels of overpasses and elevated ramps, boats floated on the Lachine Canal and trains chugged with freight. In an especially futuristic touch, two continuous bands of fluorescent lights glowed from the highway’s walls. Driving on it, the city unfolded before you: a skyline studded with smokestacks and steeples and the slow blink of the Farine Five Roses sign. More than a mega-project, the Turcot was a modernist victory cry.

The Turcot still inspires, but, like any relic of a bygone era, its sheen has worn away. The railyards that once spread out from the interchange—and from which the Turcot took its name—were closed by Canadian National in 2002. Ordinary highway lights replaced the space-age illuminations when the aluminum wiring decayed. Winter road salt has soaked the structure in a corrosive brine, inflating steel reinforcement bars into rusted balloons ten times their original size, causing concrete to drop off in chunks.

In 2007, the Ministère des transports du Québec (MTQ) proposed tearing the whole thing down and building a new ground-level interchange in its place. According to the renderings, vehicular capacity would be increased by 20 percent, but the new interchange—projected to cost $1.5 billion over seven years—would require the demolition of two hundred homes, including an entire street of walkup apartments and a large loft building that housed more than four hundred people. Its embankments would cut off links between St. Henri, Côte-St.-Paul and the other working-class areas adjacent to the interchange.

Unsurprisingly, the Turcot changes have proven controversial. Wander around St. Henri—the neighbourhood with the most to lose from the new interchange—and you’ll see “Mobilisation Turcot” posters everywhere, referring to the protest movement sparked by the MTQ’s plans. People are justifiably worried that the rebuilt Turcot will pump more cars onto their streets and more pollution into the atmosphere. But the Turcot has become more than just a community issue.

Over the past several years, Montreal has spent billions reinvesting in public transit and creating an impressive cycling infrastructure, including new bike lanes, on-street bike parking and a popular public bike-sharing system. The MTQ’s Turcot plan seems at odds with Montreal’s efforts to become more sustainable and less car-reliant. “The MTQ are focused mainly with getting cars and trucks to move as freely and quickly as possible,” explains Raphaël Fischler, an urban planning professor at McGill University. “They look at it from a very functional perspective. But their plan has to be pushed to be more environmentally sensitive, which means sensitivity to urban design as well as the natural environment.”

The province’s environmental assessment commission agrees. The Bureau d’audiences publiques sur l’environnement (BAPE) assessed the MTQ’s plans and proposed “reconfiguring the project” to mitigate its impact on Montreal’s urban ecology. So the MTQ has gone back to the drawing board.

But what form should an alternative Turcot take? Other cities around the world, faced with similar dilemmas, have come up with remarkable solutions. In 1976, Seoul built an elevated expressway over Cheonggyecheon, a once-graceful stream that ran through the old imperial heart of the South Korean capital. After the Korean War, the waterway had become covered with roads and concrete as factories and warehouses sprung up along its banks. By the time the expressway was built, there wasn’t much of a stream left. Photos from the 1980s and nineties show a Cheonggyecheon Expressway clogged with cars and trucks making their way toward central Seoul’s forest of skyscrapers.

Safety evaluations soon revealed the expressway was deteriorating rapidly, and by 2001, $100 billion in repairs were needed to keep the structure from collapsing. Rather than embark on what threatened to be an endless cycle of reconstruction, Seoul officials decided, in 2003, to go a different way altogether. In two years they demolished the expressway and roads covering the stream, restored two ancient bridges and created a beautifully landscaped park along the path of the water. Three decades as a virtual sewer had left Cheonggyecheon nearly dry, so one hundred thousand tons of water were pumped into the stream from a nearby treatment plant, giving it an average depth of about half a metre.

When Cheonggyecheon reopened in 2005, it had an immediate impact. In the summer, temperatures along the watercourse are more than three degrees cooler than in other parts of the city. Seoul’s own sense of itself as a fast-paced, ultra-urban city also changed. Cheonggyecheon’s banks are now lined by a promenade of wild grasses and rough-cut stone, giving the area a curiously rural feel; stepping stones, placed along the stream at regular intervals, create a playful, improvisational quality. It’s now the kind of place where you’re likely to glimpse a canoodling couple roll up their jeans and wade in.

Most surprisingly, the Cheonggyecheon project has reduced traffic congestion. Not only has the number of cars decreased 2.6 percent since the expressway was removed, but more people now use the bus and metro to enter the city centre. It’s a perfect example of the Braess Paradox. In 1968, the mathematician Dietrich Braess observed that adding capacity to a road network can sometimes result in a less efficient flow of traffic, and that reducing capacity can increase efficiency. One hypothesis is that, because drivers selfishly choose the route that seems shortest to them, the dispersal of cars between existing routes and newer, supposedly quicker alternatives results in more traffic jams.

This paradox was given another demonstration when San Francisco’s Embarcadero Freeway and Central Freeway were demolished in 1991 and 2003, respectively. Against expectations, congestion improved.
 “What happened with the Central was that they had to temporarily close it to demolish the upper deck, and while it was closed, people got used to not having it around,” says Steve Boland, an urban planner who lives near the freeway’s former path. “On the day it closed, there were news helicopters hovering overhead, just waiting for the traffic apocalypse. But it never materialized. Drivers adjusted and either distributed themselves over the grid, or didn’t make as many trips.”

In Paris, an expressway has disappeared in a very different way. For most of the year, traffic rips along the Voie Georges Pompidou, a limited-access arterial on the right bank of the Seine. Every summer since 2002, though, its lanes are converted into a 3.5-kilometre beach that combines the Parisian love of sun-lounging with the town’s summertime exodus for the beach. Sand is spread over the roadway, palm trees are planted and chaise lounges set up along the riverside. With imagination and relatively little effort, a space once reserved exclusively for cars and trucks is transformed into an oasis.

Paris-Plage’s popularity—its debut drew over two million people—proves that if you can’t raze an expressway, there are other ways to reduce its impact. Last December, Hong Kong held an international competition to design a noise barrier for the Gascoigne Road Flyover, an elevated roadway that runs through one of the most crowded parts of the city. The winning entry—apparently inspired by the indigenous Banyan trees that grow from old stone walls found in the hillier parts of Hong Kong—came from a team of local architecture graduates who proposed encasing the road in a tube of vegetation-covered glass slates. Such a noise barrier would not only make the neighbourhood around the road quieter, it also would cut air pollution and provide residents with a floating garden.

Why are all these unconventional highway solutions relevant to the Turcot? Because they show that complicated infrastructural dilemmas require creative, out-of-the-box thinking, and that sometimes the most radical answer is the best one. Last year, a number of writers and academics published Montreal at the Crossroads: Superhighways, the Turcot and the Environment, a book on the challenges and opportunities presented by the interchange. One contributor, architect Peter Sijpkes, makes a bold pitch: don’t touch a thing. Sijpkes recommends we reinforce the Turcot’s existing structure with steel beams, keeping it more or less as is, and instead find ways of using the empty acres underneath—space that would go to waste if the Turcot were replaced by a ground-level interchange.

Other cities have made good use of the areas beneath their elevated highways. In London, playing fields, community centres and retail arcades were built below the Westway, which runs through the western suburbs. You’ll also find public markets and plazas under many flyovers in Hong Kong. If the Turcot is kept intact, other intriguing solutions may emerge. It could be filled with trees, shrubs and plants to create the world’s largest vertical arboretum. It could be closed entirely to traffic and turned into a vast aerial promenade.

Nothing makes you feel smaller than standing beneath the Turcot. It was Montreal’s most ballsy foray into the Big Thinking era of the 1960s, when history’s march toward technological utopia was deemed inevitable. Things have changed since then. Montreal never morphed into the global metropolis it seemed destined to become, and grand, unilateral gestures are totally dépassé. But now that the BAPE has ordered the MTQ to reconsider its approach to the interchange, there’s no reason why that big thinking has to end.

See the rest of Issue 35 (Spring 2010).

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