'The war on the car is over." Rob Ford made that statement on his first day as mayor in 2010, and it was one of the emotional through-lines of his time as mayor. Bike lanes? Mass transit that runs on the surface? Better urban design? All of them assaults, as Mr. Ford framed it, on the everyday folks who get around by driving.

On the week that Mr. Ford's body will lie in repose at City Hall, the forces of the automobile are poised for a victory. When council meets, it seems ready to spend vast amounts of money on a piece of infrastructure that would make it easier for a few drivers to get to the heart of downtown – rebuilding the east end of the Gardiner expressway.

It could be a love-in. Councillors will look at a $1.052-billion proposal, called the "Hybrid 3," to rebuild a lightly used, 1.7-kilometre stretch of the Gardiner East. It comes unanimously recommended by the public works and infrastructure committee. Chair Jaye Robinson, three weeks ago, called it "a win-win-win-win-win."

Story continues below advertisement

But she got it almost exactly backward: The plan is terrible urban design, muddled transportation planning and a squandering of $600-million in public money – a cost set to climb even higher if construction unearths surprise delays. If it passes, it will be the most wasteful decision to come out of City Hall in at least a decade.

Last June, council decided against tearing down the highway and replacing it with a "boulevard" – ramping down the Gardiner East to merge it with an enlarged Lake Shore Boulevard. This plan carried an estimated price tag of $461-million, and it was better by every measure. It lost. This week's debate is about how to rebuild an elevated expressway without doing too much damage to the city.

How did we get here? And why should city council make a U-turn?

1. There are two Gardiners

"There are two different roads on the Gardiner," councillor Shelley Carroll said this week. "One that is used a lot, and one that is used a little." If you imagine the Gardiner Expressway, you are probably thinking about the western end of it – the site of daily bumper-to-bumper traffic. Across town, between Jarvis and the Don Valley Parkway, it's a different story.

Just ask Ms. Carroll, who represents Ward 33 Don Valley East and drives the highway frequently. "When I get on, I know that I'll be able to travel at 120 klicks all the way to the DVP. There is not the same usage of that road in any way, shape or form as there is in the east." And those who drive downtown on the DVP in rush hour, including many of Ms. Carroll's uptown constituents, largely get off the highway at the Richmond Street exit: About half of southbound traffic on the DVP, according to city figures, leaves there before hitting the westbound lanes of the Gardiner East.

2. The Gardiner East isn't full – even when it's supposed to be

Story continues below advertisement

Highways are empty most of the time; governments build them to be full in "peak hours," i.e., rush hour. But this one isn't full, even then: About 4,500 cars an hour drive it at the peak, significantly fewer than on the other side of downtown.

Before last June's debate at council, Mayor John Tory rode down the DVP with a TV crew and did a live spot talking up the need to maintain the expressway. The Gardiner East had a truck stalled in one lane – cutting its capacity by one-third – and yet traffic was still moving. Somehow, Mr. Tory didn't see that as a clear sign that the highway is overbuilt. Merging it with Lake Shore, which lies right underneath it, would create a single road that could comfortably handle the traffic. Drivers would continue on almost the same route, according to city consultants, with delays of two or three minutes, and even that is pessimistic – in reality, people are likely to choose other routes entirely.

3. There are huge question marks

To build a boulevard, you lay down asphalt. To build an elevated highway, you have to dig foundations. The new "Hybrid" Gardiner would be a large and complex piece of infrastructure, and it'll disturb some dirty soil; the route runs through an area long used for industry and an oil tank farm. Nobody knows what the real costs of remediating, or cleaning, that soil will be. This is one reason that city staff, in a report to council, cited "a potential variance of up to plus/minus 20 per cent" in the capital costs.

Bet on the plus, not the minus. Ms. Carroll said this week that her best guess is that costs will rise by $200-million – which means the $600-million extra cost of the hybrid, over the boulevard, could rise to $800-million.

4. The future of downtown Toronto is at stake

Story continues below advertisement

The Gardiner East cuts through an area, at the mouth of the Don River, that is a blank slate – for now. But this land, known as the Keating Channel Precinct, is part of the massive 2,000-acre area being planned and redeveloped by Waterfront Toronto to house 40,000 new residences and more. (That is more than twice the population of Leaside.) So far, that agency has spent $1.5-billion on new infrastructure and public spaces, all of them excellent.

And guess what the effect is of running a highway through a residential area? The highway's "continued presence remains a blight," local resident and community activist Julie Beddoes said at the public works and infrastructure committee meeting March. "The city is obliged to consider its effects on neighbourhoods."

The new proposal is better than the "hybrid" that was under discussion in June. City staff have massaged it, admirably, so that the highway runs alongside rather than through the new district. It could have been much worse.

And too often that's just how big planning decisions get made in this city: by compromise between good ideas and terrible ones. This is the sort of bargain you make if you are negotiating a peace treaty. But are we trying to end a "war"? Or build a city?

Editor's note: An earlier version of this article incorrectly said about 1,800 cars an hour drive the Gardiner East at the peak, about one-third of the number on the west end of downtown. In fact, about 4,500 cars an hour drive the Gardiner East at the peak, about one-half the number on the west end. Also, the article incorrectly said two-thirds of soutbound traffic on the DVP, according to city figures, leaves there before hitting the westbound lanes of the Gardiner East. In fact, the number is approximately half.