An iconic new bridge will soon span Toronto's Don River, planned to carry the Ontario Line subway route across the waterway in style.

The planned Lower Don Bridge promises to be a jewel in the crown of the new 15.6-km subway line linking Exhibition Place with the Ontario Science Centre.

First announced in 2021, the arch bridge is planned to span the Don River just north of Lake Shore Boulevard, and will function as a widening of the existing rail bridge that currently crosses the river.

Plans for the bridge advanced in August 2022, when Metrolinx awarded a construction contract for the project. Since that time, early works for the project have commenced.

As construction begins, the province has offered the public another tease of the project, releasing new images of the planned Lower Don Bridge that highlight architectural uplighting that will illuminate the structure after dark.

🌉 We're building a new Lower Don Bridge to carry Ontario Line trains over the Don River - but it's so much more than just a rail bridge. This new bridge will become an illuminating part of the urban landscape from dusk to dawn. 🌆

Learn more: https://t.co/SVEMlrUC4a pic.twitter.com/w7dpoHaBHL

— Ontario Line (@OntarioLine) August 28, 2023

Metrolinx has explained the rationale for the arch design, stating that it allows the bridge to be constructed in an environmentally responsible manner and does not require bridge piers to be built within the river itself, instead placing its supports on the river's banks.

In 2021, Maria Zintchenko, a project manager at Metrolinx, said, "We are clear spanning over the DVP and Don River and working with the Toronto and Region Conservation Authority to ensure there are no flood concerns."

In addition to its environmental advantages over other designs, the arch plan was selected for an aesthetic that responds to existing architecture and infrastructure in the area.

Andre Marois, Metrolinx director of corridor infrastructure, stated in 2021 that the design "ties in with its surroundings in the East Waterfront, including the new bridges to the south of it, built by Waterfront Toronto for the Port Lands project, which are also arch structures."

Construction for the Ontario Line is currently expected to be completed in 2030.