High-speed 300km/h rail line from Toronto could include huge tunnels

Toronto could become the site of even more major rail tunnels as part of a proposed high-speed rail network between Toronto and Quebec City, according to new details from Alto, the federal Crown corporation leading the project.

In an update on its website, Alto says it is actively studying ways to bring the high-speed trains into downtown Toronto by tunnelling "from the north of the east," or using elevated tracks, with service terminating at either Union Station or a nearby location.

The update also confirms that Alto plans to begin tunnelling from north of the river that borders Montreal's north side to downtown.

"To reach Montreal, the current hypothesis involves building a tunnel under the Rivière des Prairies and Mount Royal to access downtown directly, reducing integration challenges in a dense urban setting," Alto's website reads.

Although the tunnelling would drive up costs dramatically, Alto stresses that the investment can prove to be cheaper over its life cycle. Final decisions regarding funding have not yet been made for the rail line, but construction on the first segment of the 1,000-kilometre corridor between Montreal and Ottawa is slated to start in 2029.

Alto estimates that the transit project, which will be Canada's first high-speed rail network, will boost GDP by up to $35 billion once in operation.

The rail line is set to reach speeds of up to 300 km/hour, create 51,000 jobs during construction, and cut travel times in half, making for a three-hour trip between Toronto and Montreal. The line's stops include Toronto, Peterborough, Ottawa, Laval, Montreal, Trois-Rivières, and Quebec City.

In its update, the federal Crown corporation also said that it is considering two potential corridors between Ottawa and Peterborough, with one serving as a more direct line while the other curves closer to Lake Ontario.

While the first option reduces travel distance, it also "involves complex work in remote and sensitive areas," with rock formations. On the other hand, the second option offers a more straightforward construction process, but it does run through several densely populated areas.

Starting on Wednesday, Alto is set to embark on a three-month-long consultation process through open houses and virtual sessions, where Canadian residents will have the chance to share their views on the corridor.

Consultations will inform the selection of the line’s preferred alignment and station locations.