In the heart of Downtown Toronto, tucked well south of Front Street’s iconic limestone façade, ongoing work to expand and modernize Union Station has made significant progress since the start of Metrolinx‘s Union Station Enhancement Project in February, 2022. After nearly a century of service following their installation in 1929, the rail hub’s passenger platforms are undergoing major changes to improve passenger flow, rail capacity, and access from the surrounding Financial District and South Core.

Looking west towards the under-construction South Concourse and platforms, as concrete is being poured into vast formwork, April 2025, image courtesy of Metrolinx

Constructed in an era when most passengers arrived with suitcases, Union Station’s platforms were designed primarily to accommodate inter-city trains and the copious amounts of baggage, mail, and parcels that entered the city by rail each day. As a result, there are numerous narrow, poorly connected platforms that have become a constant source of frustration for today’s crush of commuters and visitors alike, with long queues a frequent sight at the stairwells and escalators that connect riders to the concourses below track level.

Looking east over Union Station and its trainshed prior to the start of construction on the Union Station Enhancement Project in 2022, image courtesy of Metrolinx.

As GO Transit has continuously improved and expanded commuter rail service across the Greater Toronto Area since its inception in 1967, Union Station’s capacity has become increasingly strained. With plans to further enhance service levels through tens of billions of dollars in investment across the GO network, Union Station and its surrounding rail corridor require major upgrades.

Starting in 2010, a generational renovation of the Great Hall and concourse areas was begun, led by the City of Toronto. By 2021, the initial phase provided a new York Street Concourse, an entirely rebuilt Bay Street Concourse, improved PATH connections, and significant retail additions bringing Union Station firmly into the 21st century.

The rebuilt Bay Concourse, completed in 2021 after over a decade of work, image courtesy of Metrolinx

As work on the Bay and York Concourses neared completion in 2020, Infrastructure Ontario issued a request for proposals (RFP) for the next phase of improvements to Union Station, a phase considered crucial for creating a truly world-standard, electrified regional rail network. Dubbed the Union Station Enhancement Project (USEP), several existing platforms would be demolished as part of this proposal, then consolidated to create a smaller number of wider platforms with improved accessibility. 

When all phases of the USEP are completed, Metrolinx estimates that rail capacity at Union Station will be quadrupled, allowing for up to 80 trains per hour. The project will also increase permitted train speeds through the Union Station Rail Corridor to as high as 72 km/h, ending decades of slow, crawling movements as trains enter and exit Union Station.

A rendering of a future platform following the completion of USEP, featuring wider platform areas and additional staircases and elevators, image courtesy of Metrolinx

To facilitate the eventual full rehabilitation of Union Station’s platforms, and all of the construction impacts on the York and Bay Concourses that will necessitate, a new “South Concourse” and platforms are being constructed where platforms 24, 25, 26 and 27 once stood, as detailed in the diagram below. 

Diagram depicting current and U/C platform arrangement at Union Station, composed of many narrow platforms with congested stairs, image courtesy of UrbanToronto forum contributor WB62

Located at the very southern edge of the Union Station Rail Corridor (USRC) and beyond the existing trainshed, these less intensively used platforms were deemed an optimal place to start the enhancement program so as to avoid extensive service disruptions and construction complications.

A section cut diagram displaying where the new South Concourse and platforms are being constructed, image courtesy of Metrolinx

The reconstruction of platforms 24 through 27 is only the first step in a series of construction phases that will reshape Union Station over the coming years. Once the new South Concourse is complete, Lakeshore West and Lakeshore East trains will begin using the new southernmost platforms. These platforms have been designed to support future catenary infrastructure, positioning the Lakeshore lines to be the first to undergo electrification after their move to the modernized platforms, with the Kitchener Line and Union-Pearson Express to follow.

Once the Lakeshore trains have shifted south, work will gradually progress northward. Approximately every second track will be removed to allow the remaining platforms to be widened. At the same time, platforms will be lengthened east and west along the USRC to enable platform splitting, boosting capacity and operational flexibility. Some new platforms will also be added for terminating (non through-running) trains at the east and west ends of the station. Together, the widening and lengthening works will support the installation of at least 17 new staircases and elevators, improving passenger flow and accessibility throughout the station.

A diagram depicting the projected future platform arrangement at Union Station, following the consolidation of platforms to create larger, more accessible platforms, image courtesy of UrbanToronto forum contributor WB62

Since work got underway in February of 2022, major progress has been made on the below grade structure that will soon host the new South Concourse, while supporting the load of modernized tracks and platforms situated above. Construction in such a complex environment represents a genuine civic marvel, with few other projects in Canada reaching the same level of complexity and scale. Work must occur without seriously impeding the flow of the 300,000 riders who pass through Union Station on hundreds of GO trains, subways and streetcars each day, all of which requires a complex rail signalling system to ensure safe and reliable operations.

The under-construction South Concourse, November 2025, image courtesy of Metrolinx

Unlike the north-south oriented York and Bay Concourses, the South Concourse will run uninterrupted along the length of Union Station from York Street in the west to Bay Street in the east, albeit with some grade changes. Enabling improved connections to the York, Bay and VIA Concourses, as well as Union Square and Scotiabank Arena, the South Concourse will provide a much-needed capacity increase at Union Station, reducing choke points and easing passenger circulation.

A rendering of the under-construction South Concourse that will run continuously from York Street to Bay Street, image courtesy of Metrolinx

While Metrolinx has not yet put a date on the opening of the South Concourse and its new platforms above, the substantial progress already made on the new station facilities begs the question whether a mid-to-late 2026 opening may be achievable.

Looking southwest toward the under-construction South Concourse and platforms, as the future elevated park being built as part of CIBC Square nears completion, July 2025, image courtesy of UrbanToronto forum contributor Civdis

UrbanToronto will continue to follow progress on this development, but in the meantime, you can learn more about it from our Database file, linked below. If you’d like, you can join in on the conversation in the associated Project Forum thread or leave a comment in the space provided on this page.

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UrbanToronto’s research and data service, UTPro, provides comprehensive data on construction projects in the Greater Golden Horseshoe—from proposal through to completion. Other services include Instant Reports, downloadable snapshots based on location, and a daily subscription newsletter, New Development Insider, that tracks projects from initial application.