Reverting to LRT in Scarborough instead of the one-stop subway extension favoured by Mayor John Tory would require a raft of changes, potentially impacting the wider transit plan for the area, a TTC briefing note obtained by CP24 suggests.

While the TTC estimates construction of the seven-stop LRT itself to cost $2.98 billion versus $3.16 billion for the Scarborough subway, there are a number issues that would need to be resolved, likely driving the LRT’s costs much higher.

If council voted to change gears in favour of a seven stop LRT linking Kennedy Station to Sheppard East instead of the current plan to extend Line 2 to Scarborough Town Centre, the briefing note says the line could be ready by 2026 at the earliest.

Last month, Tory told reporters the revised cost of the one-stop Scarborough subway was $3.16 billion. The City says the subway could be in operation by 2025 or 2026 at the earliest.

Tory has also promised to build a 17-stop extension of the Eglinton Crosstown LRT, linking University of Toronto Scarborough with areas to its southwest, at a cost of $1.6 billion.

If council were to revert to an LRT instead of the subway, the environmental assessment for the project would have to be amended, including how the LRT would connect to the Eglinton Crosstown LRT at Kennedy Station and new ridership forecasts.

“For that old LRT plan to be brought back, you’d basically have to re-engineer that entire station,” TTC Chair Josh Colle told CP24.

A SmartTrack station is planned for Lawrence Avenue East. The TTC briefing note says an LRT station built in the same location “would have to be reviewed with Metrolinx to identify and resolve any conflicts as the running structure is in the same corridor.”

The LRT would also need a vehicle storage and maintenance facility suitable for all of the light rail rolling stock eventually built in Scarborough. The TTC says an adequate site still needs to be identified.

The combined cost of the changes required to revert to an LRT were not specified in the briefing note.

“To a large part the technical factors make (the LRT) less and less feasible,” Colle said.

The city would also have to check with the federal government and province to see if a change in plans would threaten the money they have offered to the project.

“With the change in technology, confirmation of contributions from funding partners may be required,” the briefing note says, referring to a $660 million capital contribution from the federal government made in 2013.

Several councillors, including Josh Matlow, Janet Davis, Gord Perks and Shelley Carroll, are pushing for council to revert back to an LRT in place of the one-stop subway extension.

Coun. Matlow said in an email that a master agreement signed with provincial transit agency Metrolinx means most of the costs associated with building an LRT in place of a subway extension would be borne by Metrolinx.

When asked about the potential for the LRT’s costs to escalate, Matlow pointed to the fact that the estimated cost of the Scarborough subway extension recently increased by $1 billion.

“The question now is which one makes more sense.”