Here's how Toronto's next iconic bridge is being built

Toronto's next iconic bridge will be a huge transit landmark — and could very well be the most memorable part of your commute in the not-too-distant future. 

The new Lower Don Bridge is one of two major river crossings carrying the new 15.6-kilometre Ontario Line, set to link Exhibition Place with the now-shuttered Ontario Science Centre by 2031.

The new arch bridge will serve as a key piece of infrastructure on the line, carrying trains across the Don River and Don Valley Parkway.

Plans for the bridge, located immediately north of the existing Lower Don Bridge carrying GO train traffic, were announced in 2021.

The bridge's design is not only environmentally responsible, but also visually striking: Metrolinx is promising to deliver a 120-metre-long steel-tied arch bridge set to span the Don River just north of Lake Shore Boulevard for Ontario Line travellers, at the east side of the Don Yard. 

The new bridge will showcase a clear view over both the river and the Don Valley Parkway (DVP), and will avoid environmental impacts by placing its piers adjacent to, rather than lodged into the river below. 

Construction on the bridge kicked off in 2024. Since its initial announcement, the bridge's construction has undergone extensive early works ahead of the structural construction of the arch bridge ahead.

The Lower Don Bridge is scheduled for completion by 2027. 

In 2022, Metrolinx took a significant first step in the project by awarding a construction contract for the bridge and Don Yard, which enabled early work on the bridge to commence. 

Before construction could begin, Metrolinx crews cleared the area in 2023, which included relocating a water main and shifting existing train tracks, so that the Ontario Line could run alongside the GO Trains in the shared rail corridor. 

Work on the tracks was also necessary to ensure continued GO Train service during the construction period.  This meant changes in traffic and ongoing construction noise, but the process maintained transit connections and efficiency. 

Construction on the east support structure also began in spring 2024 with the installation of the first two piers, which form the bridge's foundation.  Once that is completed, work will be underway on the west side of the bridge. 

A temporary bridge is currently being installed by Metrolinx, serving as an access ramp and platform for Metrolinx crews to assemble the permanent bridge on-site. 

Parts needed for the Lower Don Bridge are being constructed in Nova Scotia and shipped to Toronto, where they will then be assembled.

Having the temporary bridge will minimize disruption in the area, meaning the DVP will only be required to close overnight for a few weekends.

The Lower Don Bridge is scheduled for completion by 2027, while the Ontario Line is expected to be completed by 2031.