Construction for the new Ontario Line is transforming sites across Toronto, as demolitions, station construction, and the creation of new bridges lay the groundwork for this game-changing 15-station subway route. The Ontario Line's route will cross Toronto's Don River twice over its 15.6km path, requiring a pair of bridges unlike anything constructed in the city for generations. First announced in 2021, the arch-supported structure — dubbed the Lower Don Bridge — commenced construction in 2024 and is now progressing quickly after roughly a year and a half of work. Once complete, the arch bridge — with curved supports illuminated by architectural lighting — promises to be one of the signature visual features of the Ontario Line. Crews have been hard at work setting the stage for the Lower Don Bridge, and Metrolinx shared an update on Tuesday outlining the current progress on this much-anticipated landmark.