The city had a groundbreaking ceremony Monday to mark the start of construction on the Sheppard Avenue Light Rail Transit line.
The project's funding is coming from the federal and provincial governments as well as the city, but the question of funding the 14-kilometre line's operating costs when it opens in 2013 isn't answered yet.
"By 2013, we'll have sorted that out," Mayor David Miller told reporters. "We're having discussions with the province. That'll come, I'm absolutely confident."
He added: "The sad thing is that the project should have happened 20 years ago. The thing I'm proud of is they're happening now."
The line's westernmost point will be Don Mills subway station, where it will tie into York Region's Viva transit system. It will go eastward to Meadowvale, with a stop at the Agincourt GO Transit station, and potentially into Durham Region.
That part of Toronto is currently served by the 85 Sheppard East and 190 Scarborough Centre Rocket buses, which will be ended when the LRT opens. The ridership was estimated to be nine million in 2006, and will rise to 20 million by 2021.
The LRT line will travel under Highway 404 and enter Don Mills station. It will have dedicated lanes on Sheppard Avenue.
The budgeted cost for constructing the line is just under $1 billion.
The Sheppard Avenue East project is part of Transit City, an ambition plan to create a 120-kilometre network of light rail transit in Toronto's outer neighbourhoods.
With a report from CTV Toronto's Alicia Markson
