Tunnelling Begins for Ontario Line Under Toronto Core

Tunnelling work has officially begun for the downtown section of the Ontario Line, marking a major milestone in one of Canada’s largest transit developments. The announcement was made by Doug Ford, who described the start of underground construction as a historic moment for the city.

Two tunnel boring machines are now set to dig twin tunnels stretching approximately six kilometres beneath downtown Toronto. The tunnels will run from near Exhibition Station to an area west of the Don River, reaching depths of up to 40 metres below ground. This is the first time in more than 60 years that new subway tunnels are being constructed under the city’s core.

The announcement was made alongside key officials, including Transportation Minister Prabmeet Sarkaria and Toronto Mayor Olivia Chow. Officials described the development as a critical step forward, signalling progress from planning to active construction.

The Ontario Line, first introduced in 2019, is a 15.6-kilometre subway route designed to ease congestion on Toronto’s transit network. Once completed, it will include 15 stations, running from Eglinton and Don Mills to Exhibition Place. The line will connect with multiple transit systems, including existing subway lines and regional train services.

Despite the progress, officials noted that the project remains highly complex. Metrolinx CEO Michael Lindsay said that while tunnelling is a significant milestone, it represents only one part of the broader construction effort. The expected completion timeline is now set for the early 2030s.

The project’s cost has also increased significantly, with current estimates reaching $29.5 billion, compared to the original projection of $10.9 billion. The federal government has committed $4 billion toward the project’s funding.

When completed, the Ontario Line is expected to carry nearly 400,000 passengers daily, helping reduce overcrowding on existing routes, particularly Toronto’s busiest subway lines. Officials estimate that peak-hour congestion could be reduced by up to 15 percent in some areas.

In addition to transit improvements, the project is expected to support urban development. The province has highlighted plans for transit-oriented communities along the route, which could add around 15,000 new homes. However, some concerns have been raised after recent design renderings showed limited residential development integrated with station infrastructure.

Overall, the start of tunnelling marks a key phase in transforming Toronto’s public transit system, though challenges related to cost, timeline, and urban planning remain under close watch.