
Toronto has started tunnelling on its new subway route. The Ontario Line will open up 15 stops between Exhibition Place, west of downtown, and the old location of the Ontario Science Centre in North York. The project is over 15 kilometres long, with more than half of the line running underground .
The subway is a joint project between the city’s Toronto Transit Commission and the provincial Metrolinx transportation agency.
Ontario Premier Doug Ford said in a Facebook post last week that the Ontario Line will create 40 new connections to existing transit routes, “will put nearly 230,000 people” closer to transit, and will “support 4,700,” new Ontario jobs.
“The start of tunnelling is a historic milestone for the Ontario Line which, once complete, will help cut travel times for commuters across Toronto by 40 minutes,” Ford said in a press release.
Here’s everything you need to know about the Ontario Line.
When will it be completed?
When the Ontario Line was first announced in 2019, Metrolinx estimated it would be completed by 2027 . Now, the transit agency won’t set a firm date for its completion.
“We think we’re still trending towards the early 2030s to be done with civil infrastructure,” Metrolinx CEO Michael Lindsay said at a press conference in February.
After that, the subway line would still need to be tested.
How much will it cost?
The initial proposal for this line set the estimated cost under $11 billion . The total investment for the four major GTA transit projects — the Scarborough extension, the Eglinton Crosstown, the Ontario Line, and the Yonge North extension — was $26.8 billion as of May 2021.
Metrolinx declined to give an update on the cost of the Ontario Line. However, a senior government source told Global News in 2024 that the cost of the Ontario Line project alone had increased to $27.2 billion .
The federal government is contributing more than $4 billion to the project.
How will construction affect traffic?
The construction will cause temporary planned and unplanned road closures on major streets and highways .
Andrew Hope, Metrolinx chief capital officer, said in February at a board of directors meeting that the route has already caused a two-lane closure on the Gardiner Expressway.
The line will include three bridges over the Don River and in February, the Metrolinx CEO also said construction could shut down the Don Valley Parkway.
“These are formidable works,” Lindsay said. “If you think about it, we are building the Bloor viaduct again three times for this project, but these are massive works. We will work with all partners to minimize disruptions to people (and) vehicles on the DVP.”
Beginning Sunday, lanes and sidewalks along the west side of Don Mills Road between Eglinton Avenue East and St. Dennis Drive will close for about five weeks, allowing construction teams to build a new temporary platform. The intersection at Don Mills Road and Gateway Boulevard will be particularly affected through May, as construction starts on a new station

How did construction go on previous transit projects?
The TTC opened Line Five (the Eglinton Crosstown LRT) in February. It runs along Eglinton Avenue and has 25 stations. The Eglinton Crosstown LRT took 15 years to complete following the start of construction, disrupting commuters, local businesses and daily traffic for six years longer than originally planned.
“It goes without saying that this line took much longer to deliver than any of us would have wanted or expected,” Lindsay said in a February Metrolinx board meeting.
The Metrolinx CEO said that their “private sector partner at the time of giving us a bid for this project, underestimated the complexity, the risk, and the challenge,” the Eglinton Crosstown construction would pose to civil infrastructure.
The Line 5 budget was originally set at $11 billion in 2007 but it grew by $2 billion over 15 years. In all, the Ontario government spent $13 billion.
Construction on the new Ontario Line subway began shortly after the completion of Line 5, raising public concern about potential cost overruns and delays.