It's the ultimate political hot potato.

For 30 years, Toronto council has kept passing the issue of extending the Scarborough subway on to the next term — with no one willing to build or bury the project.

Now, its costs have grown while its length has shrunk to one stop. Most recent municipal estimates put the project's costs between $2.9 billion to $3.2 billion.

But there's been a growing voice of dissent since the new costs, up from $2 billion, were announced in June. 

This week, Coun. Paul Ainslie said he will submit a motion to council to scrap the subway and return to its plan of a seven-stop, light rail system running east of Kennedy station.

"I still get people that say, 'Scarborough deserves a subway,'" the representative for Scarborough East said. "And if it was the most cost-effective manner for moving the most people, I'd be all for it."

But it's not, he argued — especially compared to light rail transit.

A return to light rail?

Ottawa and the provincial government had already agreed to fund construction of the proposed $1.9 billion LRT, with Queen's Park agreeing to shoulder ongoing capital maintenance as well.

The city sunk roughly $75 million into its planning, design and environmental assessment before council voted in October 2013 to abandon the LRT plan.

Although Toronto Mayor John Tory inherited that decision, it's one that he championed both during his election campaign and now that he's in office.

That's because he believes connecting Kennedy station directly with the Scarborough Civic Centre will create a development hub and "stimulate much-needed jobs and investment" there.

"It's been stagnant economically," he said in an interview on CBC's Metro Morning on Monday. "And we have to change that."

Toronto Mayor John Tory

Toronto Mayor John Tory says that an express subway to Scarborough Centre is critical to the region's economic development. (David Donnelly/CBC)

Demographer David Foot says increased transit options are, in fact, critical to Scarborough's growth and success. The district's lower household income suggests fewer families will own two cars, even though they will likely have two breadwinners, he said.

But although the district has seen density build up around the Scarborough RT stations since they opened in 1985, Foot said that's not necessarily an indicator of growth around future stations. Since then, jobs have dispersed throughout the Greater Toronto Area and fewer people are commuting downtown for work.

Value for money

Council needs to set politics aside and look at what type of transit will actually get the most people where they need to go at the most reasonable cost, both transportation expert Steven Farber and Ainslie say.

While Farber advocates turning some of the existing bus routes into a rapid transit network, he said that the seven-stop LRT provides better cost for value than would a one-stop subway.

"The notion of building a multi-billion dollar hole for one station is absolutely absurd." - Steven Farber, transportation expert and human geography professor

"Having something with a bigger spatial footprint makes more sense," the human geography professor at the University of Toronto said. "The notion of building a multi-billion dollar hole for one station is absolutely absurd."

Reviving the LRT — scrapped in a 24-20 vote during former mayor Rob Ford's "subways, subways, subways" era — would allow the city to recover some of the roughly $75 million it invested in the system's design, Ainslie said.

"It's all been studied and it's ready and the plans are done," Ainslie said.

Toronto could also lean on the province to help subsidize the route's operations, thanks to a master agreement signed during the LRT's development.

Through its transit arm Metrolinx, the province would be responsible for the LRT's capital maintenance costs. The two levels of government would then negotiate an "operational cost-sharing agreement," according to that master agreement.

Councillor Paul Ainslie

Toronto city Coun. Paul Ainslie plans to file a motion calling on council to revisit plans for a Scarborough LRT instead of a subway extension. (CBC)

Its proponents say the proposed LRT could build on the Scarborough RT's existing infrastructure and its ridership. About 39,000 passengers ride that route on average weekday, according to 2014 Toronto Transit Commission figures.

By 2031, a light rail system would move about 8,000 people per hour, according to a TTC report to council in 2013.

And while the proposed subway initially saw passenger forecasts of up to 14,000, the latest figures say it will peak at 7,300 riders per hour.

Those established riders would have to make do without a rapid transit system for one to three years if an LRT were built along the existing Scarborough RT line, municipal staff have noted in briefings to council. To offset that, the city would have to buy more buses to shuttle those passengers during construction.

But the city would not come close to incurring the amount of debt it would if it were to build a subway extension, Ainslie said.

Municipal staff had proposed the idea of borrowing $1 billion over 30 years and bringing in 1.6 per cent property tax levy in October 2013 when it looked at how to fund the project.

New cars for the SRT

What's forcing council to make a decision is age; after 30 years of operation — and political indecision — the Scarborough RT cars are nearing the end of their lifetime.

And while it's not an option currently before council, the logical decision is to keep the existing infrastructure and buy new Scarborough RT cars, University of Toronto civil engineering professor Richard Soberman said.

"The ridership forecasts for the subway extension are so low, why would you bother with it?" Soberman said. "The Scarborough RT was a mistake but it's there and it could be revived in a much shorter time."

Subway

The subway extension could be built without disrupting the current SRT line. (Paul Chiasson/Canadian Press)

One of the last times council considered that option — in 2006 — staff predicted they could buy new cars and refurbish the line for $360 million, with a service disruption of just eight months, according to a report Soberman prepared for a Toronto transportation summit last year.

Factor in inflation, and that's about $425 million.

Or as Soberman put it, "a fraction" of the cost of the subway extension.

When asked last week about alternatives to the proposed subway extension, a spokeswoman for chief city planner Jennifer Keesmaat said that she would not comment before the city council meetings.

The meeting, expected to take place on Wednesday, will see council set its transit priorities from now until 2031, including discussion about the Eglinton West LRT, Eglinton East LRT and the so-called Downtown Relief line.