Back in 1962, Metropolitan Toronto roads commissioner George Grant predicted that, by now, the Gardiner Expressway would be obsolete. But then, he thought, so would roads. In 50 years, Grant figured, Torontonians would get around by personal rocket, with a launching pad outside every home. “The only complaint during rush hour,” he assured the Electric Club of Toronto, “would be that, with so many rockets in the atmosphere, the sun would be hidden from the earth at times.” We never got the jetpacks, but right on cue, the Gardiner is crumbling: Five times in the past five months alone, pieces of the elevated portion of the highway have broken off and tumbled below—and those are just the ones we know about. We surveyed the damage from a safe distance.


Click here to open a full-sized .JPG charting the last 15 years of falling concrete.

THE CRUMBLING GARDINER, BY THE NUMBERS
124,000
Average number of cars that drive the elevated section of the Gardiner every weekday.

63 ½
Maximum tonnage trucks can carry on the Gardiner’s elevated portion. The one exception is if they’re carting cranes; because they’re so long, their weight is distributed across a much larger area.
6,966
Number of pedestrians who walked below the Gardiner at Lake Shore Boulevard and York Street during the busiest eight hours of Thursday, May 3, 2012, the most recent day counted.

13,677
Number of vehicles that passed under the Gardiner at that intersection during the same period.
1,200–1,500
Tons of road salt dumped each winter onto the elevated section of the expressway. Salt breaks down the structure’s reinforced concrete by corroding the steel beams inside.
5 metres
The closest any new building is allowed to come to the Gardiner, as of May 1, 2012. “Three metres was considered adequate to get the [maintenance] people in to do work,” said John Bryson, formerly the City of Toronto’s Manager of Structures and Expressways. “But now that condos are crowding us on both sides, we’re going to need more room to manoeuvre.” (Bryson, and his boss, Gordon MacMillan, director of design and construction, left their jobs abruptly last week. Officials told The Grid it was a private “personnel issue.”)

5
Number of maintenance workers who inspect the expressway for worn-out concrete. They identify problem areas by performing what’s known as a chain-drag test on the deck. Says John Bryson, “You just drag a chain and you listen, and anything hollow-sounding is an area that you need to look at.”
$110 million
Cost of building the Gardiner Expressway (1955 to 1966). Today, that translates to somewhere around $850 million.
$160 million
Expected cost, over the next 10 years, to keep the Gardiner from eroding further.
$???
Cost of tearing down the elevated section of the Gardiner today, the subject of a long line of studies going back to 1985, which have recommended everything from simply demolishing the expressway altogether to replacing it with a surface road or a tunnel. An environmental assessment on what to do with the roadway was started in 2008. It has stalled since the last municipal election.