Here's how Toronto is building a subway on top of a bridge on top of a highway
Toronto's transit network is undergoing a generational transformation, with the forthcoming Ontario Line subway set to become the crown jewel of the city's rapid transit system when it opens in the 2030s.The 15.6-kilometre, 15-station subway route between Exhibition Place and the shuttered Ontario Science Centre at Don Mills and E...
https://www.blogto.com/city/2026/03/toronto-building-subway-top-bridge-top-highway/
Broadway subway: 2nd tunnel-boring machine breaks through at City Hall station

The breakthrough comes just over a month after machine's partner, nickjnamed Elsie, also broke through at the Broadway-City Hall station site. 

Global News
Breakthrough: Broadway subway tunnel-boring machine reaches City Hall station

In a media release Friday, the Ministry of Transportation and Infrastructure said the massive piece of equipment breached the station construction site Friday afternoon.

Global News