Text by James Bow

See Also:

• VIDEO: TT Report - Ontario Line Progress (2025), by Damian Baranowski.

As an infrastructure project, the Ontario Line dates back to 2019, when it was formally announced by the Ontario Government under premier Doug Ford. Its roots, however, date back over a century. This is a story complicated by politics, demographic shifts, engineering complexities and just plain luck, as the City of Toronto strove, but failed, to build rapid transit beneath Queen Street throughout much of the twentieth century. Much of this story is covered in the history of the Bloor-Danforth subway, and in this article dedicated to the Downtown Relief Line.

The Ontario Line, when it opens (possibly in 2031), will be a 15.6 kilometre (9.7 mile) automated rapid transit line running south from its northern terminus at Eglinton Avenue and Don Mills Road. The route follows an elevated guideway south along Don Mills Road, passing Flemingdon Park, before curving right north of Overlea Boulevard to cross the west branch of the Don River and access its maintenance and storage facility at the south end of the old Leaside Industrial Park, before curving south to Overlea near Thorncliffe Park and turning west.

At Millwood Drive, the route crosses the main portion of the Don Valley on its own bridge before diving underground and following Pape Avenue to a portal near Gerrard Square. Running at grade, the line then curves southwest to follow Metrolinx's Lakeshore rail corridor past Queen and the East Harbour Area, crossing the Don River before diving underground near the Don Yard. Following bored tunnels, the Ontario line curves northwest towards Queen Street, following that street through Downtown Toronto before curving southwest at Spadina Avenue. After passing beneath the King-Bathurst intersection, the line continues southwest before coming to the surface at Metrolinx's Lakeshore rail corridor, in time to enter its southern terminus at Exhibition GO Station.

Along the way, the Ontario Line will make several connections to major local and regional transit infrastructure, including the Line 5 Eglinton-Crosstown LRT at Don Valley (formerly Science Centre) station, the Line 2 Bloor-Danforth Subway at Pape Station, the Line 1 Yonge-University Subway at Queen and Osgoode stations, and GO Transit's Lakeshore corridor at East Harbour and Exhibition stations.

As of August 2024, the current estimated cost for the line is $27 billion, up from $10.9 billion when the project was first announced, although the revised number includes the cost of operating and maintaining the line for a period of 30 years, in addition to the capital build. When the Ontario Line opens, it may be referred to as "Line 3" on TTC and Metrolinx wayfinding systems, taking over the spot vacated by the Scarborough RT whenf it closed in July 2023.

The Long Road to Downtown Relief

(For a full history of plans for the Queen Subway and the Downtown Relief Line, please see our articles here and here)

As noted earlier, the City of Toronto had plans to build a subway (albeit oftentimes a streetcar-subway) beneath Queen Street through its downtown as early as 1911. While the concept took a back seat to the construction of the Bloor-Danforth subway, it returned in the early 1980s as the Downtown Relief Line, a full-fledged subway marketed as a means to reduce pressure on the overloaded subway transfer stations at Bloor-Yonge station and St. George. This again took a back seat as municipal and provincial politics favoured building or extending subway lines into Toronto's suburbs, but returned in the early 2010s as it became clear that such extensions were unsustainable without the construction of a relief line to increase rapid transit capacity in Toronto's downtown core.

As the 2010s progressed, the City of Toronto embarked on the design of a project called Relief Line South. Four alignments were considered, centered around a traditional subway route from Pape Station (or Broadview Station) and University Avenue (either at Queen (Osgoode station) or King (St. Andrew station)). At around the same time, Metrolinx began studies on Relief Line North, extending the Relief Line South north of Danforth Avenue on various alignments towards the Don Mills/Eglinton intersection, although this did not get past the route-selection stage. 

On March 31, 2016, Toronto City Council approved a final corridor running from Pape Station south beneath Pape Avenue to Queen Street and then turning west on Queen Street (possibly rising to the surface to cross the Don River on a bridge before diving underground again), terminating at Osgoode station. By July 2016, this alignment was adjusted west from Pape via Eastern Avenue before swinging north to Queen west of the Don River.

This approval was followed by an announcement from the provincial government of Kathleen Wynne approving $150 million of funding to Metrolinx to plan and design the line. At the time, phase one, featuring eight stops, was estimated to cost $6.8 Billion to build. Despite the planning and design funding, the project itself remained unfunded. Progress continued with a 120-day Transit Project Assessment Process under the Environmental Assessment Act starting on April 16, 2018. In January 2019, Metrolinx announced that the project could be open as early as 2029.

The Province Takes Charge

Progress on Relief Line South was upended on April 10, 2019, as Ontario premier Doug Ford (elected on June 28, 2018) announced that the province would fund the construction of the Ontario line in place of the Relief Line, running beyond the Relief Line's terminals on a route from the Don Mills/Eglinton intersection to the Canadian National Exhibition grounds, with a hoped for opening date of 2027. Critics expressed skepticism about that opening date and complained about wasting the work that had been done thus far for Relief Line South, noting that design work was 15% complete.

The province's work was bolstered by the hiring, in December 2018, of UK consultant Michael Schabas, who led the team to create the plan for the Ontario Line. Possibly inspired by the London Undergrounds automated Docklands Light Railway, his team proposed an automated light metro running at frequencies of up to every 90 seconds. 

The Ontario designation for the Ontario line was partly explained as having the Ontario Science Centre and Ontario Place at either end of the line. Indeed, initial plans suggested that Ontario Place itself, rather than Exhibition GO Station, could be the western terminus for the line, bolstering Ford's controversial proposals to revamp Ontario Place from a family-oriented public venue to a casino complex. Eventually, however, Exhibition GO was selected as the western terminus for its proximity to Liberty Village and its promise of close connections to the Lakeshore GO line.

Ironically, in the years that followed, the "Ontario" destinations were removed or significantly restructured, with Ontario Place being revamped to include a controversial spa project, and the Ontario Science Centre being closed (for disputed safety reasons) ahead of a proposed relocation. The original name for the northern terminus of the line was changed from Science Centre to Don Valley in early 2025. This included the corresponding at-the-time-unopened station on the Eglinton-Crosstown LRT.

Differences Between the Ontario Line and the Relief Line

Following Ford's announcement, a brief struggle ensued between proponents of the Ontario Line and the Relief Line as differences manifested themselves between the two proposals. From the start, the Ontario Line was announced to run from the Don Mills/Eglinton intersection, past Riverside and Leslieville, through Downtown Toronto, and on to the Exhibition, but the segment from Danforth Avenue to downtown Toronto deviated significantly from the planned-for Pape-and-Queen alignment of the Relief Line, following instead the GO railway tracks to a stop serving the redeveloping East Harbour before curving northwest back to Queen. One of the reasons given for this realignment was to reduce construction costs by bringing trains to the surface, saving on underground construction.

Most significantly, while the Relief Line was directly connected to the rest of the subway network at Pape, using the same equipment as the rest of Toronto's subway system, allowing for the storage of that equipment at Greenwood Yards (but also triggering the need for a new subway yard south and west of Kipling station), the Ontario Line would be a standalone system, using lighter and shorter automated trains, much like Vancouver's Canada Line or Montreal's REM. This would require a dedicated marshaling and maintenance facility for the Ontario Line near Thorncliffe Park, which neighbours feared would prove potentially disruptive.

Building a fully separated system allowed Metrolinx to redesign the line from the ground up. The trains, built by Hitachi, would be fully driverless and operating on standard gauge. The train cars would be shorter than the trains operating on the TTC's lines 1 and 2 (20 metres instead of 23), although possibly they would be wider (3 metres instead of 2.6). Initial plans called for four-car trains to operate on the Ontario line, which raised concerns that the line would have insufficient capacity to handle demand. In response, Metrolinx claimed that automatic operation and reduced station dwell times could allow service operations with 90-second headways, which should be sufficient to meet demand. Moreover, the stations would be designed to allow the addition of a fifth car to Ontario line trains, should demand warrant. A five-car train is planned to handle a crush capacity of 750 passengers (2.5 passengers per square metre); at 40 trains per hour, this gives the Ontario line an ultimate crush capacity of 30,000 passengers per hour per direction, although its opening capacity will likely be much lower.

There was an especially strong concern from critics that the provincial government's move and its naming the line the "Ontario Line" signaled that the Ontario government intended to maintain full control over the line, possibly as a precursor of taking over operation of the rest of the Toronto subway. However, in October 2019, Toronto Mayor John Tory and Ontario Premier Doug Ford announced an agreement that had the city endorse the Ontario Line in exchange for assurances that the Toronto subway network would remain in the city's hands. This deal was brought to Toronto City Council on October 28, 2019, which approved it in a 22-3 decision.

With this agreement in place and funding secured, Metrolinx was cleared to launch the process that would bring about the construction of the line, a full 118 years after the first calls for a Queen subway surfaced. Though the project was happening, timelines were extending. By December 2020, the opening date had been shifted from 2027 to 2030. By November 2022, the opening date was pushed back to sometime in 2031. Worse, despite claims that the realignment would provide more rapid transit at lower cost, the budget for the line had also increased, from $10.9 billion to closer to $19 billion.

Designing, Planning and Procurement

As with other transit infrastructure products from the previous decade, the Ontario Line would be built through a series of public-private partnerships, including contracts for rolling stock, infrastructure, operations and maintenance. On June 2, 2020, Metrolinx and Infrastructure Ontario put out a request for qualifications from applicants who could design, build, operate and maintain the line. To ensure a manageable project, the construction of the Ontario Line was split into five sections or categories:

• Rolling stock, systems, operations and maintenance (RSSOM). This contract was awarded on November 17, 2022 to a consortium named Connect 6ix, comprising of Hitachi Rail, Transdev, Plenary Americas and Webuild. This covered: 

• the design and construction of the Ontario line's rolling stock (from Hitachi Rail) and the construction of an operations, maintenance and storage facility to house them,

• the construction of an operations control centre and a backup operations control centre to control automatic train operations in conjunction with GO Transit and the Toronto Transit Commission,

• the construction of the tracks, communications systems (including network, wifi, CCTV, passenger display systems) and traffic control systems throughout the system,

• the construction of Presto-compliant fare equipment.

• The southern tunnel section. This was awarded on November 9, 2022 to the Ontario Transit Group, comprising of Ferrovial and Vinci and included: 

• the construction of a 6-kilometre tunnel through downtown Toronto from the Don Yard west of the Don River to just east of Exhibition GO Station,

• seven stations, six of them within the tunnel, including two interchange stations at Queen-Yonge and Osgoode, the stand-alone underground stations at Corktown, Moss Park, Queen-Spadina and King-Bathurst) and the at-grade terminal station at Exhibition GO.

• The Pape tunnel and underground stations. This contract was awarded on January 17, 2024 to Pape North Connect, a consortium led by Webuild and Fomento de Construcciones y Contratas) which covered: 

• the construction of a 3-kilometre tunnel from near Gerrard Square and beneath Pape Avenue to the southern bridge over the Don Valley,

• the construction of one stand-alone station at Cosburn, and one interchange station at Pape on the Bloor-Danforth line,

• advanced civil engineering work to underpin the existing Pape station on the Bloor-Danforth subway

• additional features including emergency exit buildings and a crossover near Sammon Avenue.

• Elevated guideway and stations. Metrolinx awarded this contract on February 20, 2024 to Trillium Guideway Partners, led by Acciona and AMICO. This contract included: 

• the design and construction of a 3-kilometre long elevated guideway through the Don Valley.,

• the construction of five elevated stations, including four stand-alone stations at Riverside-Leslieville (Queen Street), Gerrard, Thorncliffe Park and Flemingdon Park, and an interchange station at Don Valley (Don Mills and Eglinton, on the Line 5 Eglinton-Crosstown LRT,

• advanced civil engineering work including emergency exit buildings, and places Ontario Line trains can stop to operate emergency exits near Metrolinx-owned rail on the Lakeshore line, or near the Thorncliffe Park storage facility.

• The joint use corridor. These were a series of smaller contracts for bridge, track and other preparatory work where the Ontario Line operated near or alongside Metrolinx's Lakeshore rail corridor, particularly around Exhibition GO Station, and the section from the Don Yard portal to Ontario Line's Gerrard station. These contracts were issued to smaller contractors that worked directly with Metrolinx and Infrastructure Ontario.

Early Construction Work and Controversy

While the procurement process continued, the Ontario government and Metrolinx moved quickly to show their commitment to building the Ontario Line by organizing a ground-breaking ceremony at Exhibition Place on March 27, 2022. This ceremony was attended by Premier Ford and Mayor Tory as well as other politicians and Metrolinx officials. In August 2022, buildings at the site of Corktown station were demolished to make way for construction in the start of 2023. Archeologists were brought in after demolition to document any historical findings from the site.

Similar prep work began at the sites of Exhibition, Queen, Corktown, Osgoode and Moss Park stations in early 2023. Work also began on the Lakeshore rail corridor, starting at Don yard and continuing east of the Don River, in preparation for the widening of the right-of-way to accommodate Ontario Line stations and tracks.

As plans developed, some controversies emerged. Late in 2021, residents of the Thorncliffe Park area objected to plans to build the Ontario Line's maintenance and storage facility in their neighbourhood. The 175,000 square-metre facility was proposed to occupy land north of Overlea Boulevard and east of Millwood Road, potentially taking over and demolishing a number of small businesses that had provided jobs for many in the local area. Residents complained that the site selection was done with minimal local consultation, and requests for other amenities, including a recreation centre, a business park and affordable housing were ignored. In particular, residents objected to the proposed demolition of an Islamic centre, and a shopping plaza containing several local businesses including a popular Halal grocery store named Iqbal Halal Foods.

Metrolinx negotiated with the Islamic Society of Toronto and came to a $49.5 million agreement to move the Islamic centre to a larger facility at 20 Overlea Boulevard, and to help relocate local businesses to other sites in Thorncliffe Park. Despite this, the local group Save TPARK continued its opposition to the location of the Maintenance and Storage Facility, for its encroachment, and the loss of potential affordable housing.

That same month, the Law Society of Ontario expressed concerns over Metrolinx's plans to expand Osgoode Station into an interchange station between the Ontario line and the University Subway, removing a significant section of the historic grounds of Osgoode Hall and the trees that stood on it. Toronto Mayor John Tory joined the Law society in their objections, with city planners suggesting that space for the new Osgoode station entrance be taken from the northbound lanes of University Avenue instead. Metrolinx countered that a shaft built there would conflict with trains running on the University line. A consultant's report issued on February 1, 2023, commissioned by the City of Toronto, concluded that the Osgoode Hall grounds were the best site for a station headhouse, but suggested that the Campbell House grounds across University Avenue could be a feasible alternate site.

Metrolinx started removing eleven trees on the Osgoode Hall grounds on February 4, only to be stopped by court injunctions filed by the Law Society of Ontario and the Haudenosaunee Development Institute. These injunctions were dismissed on February 21, 2023, and work on the tree removal continued on the Osgoode Hall site.

Other controversies included the removal of mature trees at the Moss Park station site; safety, noise and vibration concerns over the Ontario Line's route beneath the Pape Avenue Junior Public School and Pape Children's House; housing expropriations along Pape Avenue north of Danforth; noise concerns over the elevated track sections near Flemingdon Park and Riverside-Leslieville; the destruction of historic industrial properties near East Harbour station; and density and affordable housing concerns around Corktown, Gerrard and Pape stations. These did not stop construction from proceeding.

Construction Diversions Begin

On May 1, 2023, Queen Street between Bay and Victoria was closed to allow for the construction of Ontario Line's Queen station. This forced the diversion of 501 Queen streetcars. Metrolinx planned to rehabilitate and revamp the tracks on Richmond Street and Adelaide between Church and York to accommodate the detouring streetcars, including re-establishing the southbound track on York Street, which had been separated from the network at Queen and left unused for decades. New tracks were installed, and the lane painted to allow streetcars to travel on reserved right-of-way in the opposite direction of the traffic of the rest of York Street.

As these tracks were not available when Queen Street was closed (due to unexpected conflicts with area utilities discovered in late 2022), Queen streetcars had to be diverted in both directions via Broadview, Dundas and McCaul instead, with shuttle buses covering the gap. This proved too disruptive to the Queen streetcar so instead, starting in September 2023, once the tracks on Wellington Avenue had been properly rehabilitated, the 501 Queen service was split. Cars operating east from Long Branch or Humber Loop were designated 501A and turned back at McCaul Loop. Cars operating west from Neville Park were designated 501D and followed the regular route as far as Church, before turning south to King and looping via Church, Wellington, York and King. This arrangement would be the first time in decades that regular streetcar service outside the peak hour was scheduled on Wellington Avenue.

The upgraded tracks along York, Richmond and Adelaide would finally enter service on Sunday, November 10, 2024, allowing 501 Queen Streetcars to operate through the downtown core again, and bringing regularly scheduled streetcar service back to Adelaide for the first time since 1966. At that time, services on Wellington Avenue were taken up by the 503 Kingston Road streetcar, operating at intervals of ten minutes or better, seven days a week whenever the subway was open.

Tunnel, Right-of-Way and Station Progress

In early 2025, two tunnel boring machines (TBMs) were shipped from Germany to Toronto to begin the tunnelling between Exhibition GO Station and the portal at Don Yard, just east of the Don River. Metrolinx celebrated the arrival of these two machines with a naming contest, inviting everyone to suggest names by June 23, 2025, for a chance to be honoured at the launching ceremony. On November 20, Metrolinx picked from more than 900 submissions and announced that the TBMs would be named Libby and Corkie; cutesy variants on Liberty Village and Corktown. Jason Paris was credited with the winning submission. 

The tunnel boring machines arrived from Germany at the port in Oshawa Ontario on June 9, with the machines set to start work on the downtown tunnel in early 2026. More machines will be purchased for the Pape Tunnel, but as of July 2025, no deals have been finalized.

A Tour of the Ontario Line

Don Valley Station

The Ontario Line will begin at an elevated station located at the northeast corner of the Don Mills/Eglinton intersection. Passengers can transfer to and from the underground Line 5 Eglinton-Crosstown LRT through either the station's northeast or southwest entrances, as well as through the adjacent bus terminal. Like all the other stations on the Ontario line, Don Valley will be fully accessible, with elevators in place to bring passengers from the underground platforms to the surface, to the elevated platforms. All Ontario Line stations will also open with platform doors in place, for improved climate control, and to prevent passengers from falling on the tracks.

The Ontario Line station itself will have side platforms. It is not known as yet if incoming trains will cross over, arrive and depart from a single platform, or if it will pull into a arrival platform, proceed into the tail tracks, switch ends and return via the departure platform. Tail tracks running north from this station will pass Wynford Drive, leaving room to store trains, as well as providing for a future extension to the north towards Don Mills station on Line 4 Sheppard.

Leaving Don Valley station, Ontario Line trains will follow an elevated guideway, crossing Eglinton Avenue before crossing to the west side of Don Mills Road, heading south to Flemingdon Park station at the northwest corner of Don Mills Road and Gateway Boulevard.

Flemingdon Park Station

Flemingdon Park station will be built on the site of an old parking lot serving the Ontario Science Centre. Indeed, it was noted that the station itself was closer to the main entrance of the Science Centre than Science Centre station would have been. As the Science Centre has been closed, and Line 5 Eglinton's Science Centre station renamed Don Valley, this point is now moot. As of this writing (June 2025), the design of the station and the location of its entrances have not been revealed, but the station will likely be located one level over its street entrances and feature side platforms.

From here, the elevated guideway turns west, following a Hydro right-of-way to cross the west branch of the Don River via a new bridge. At the other side of the valley, the route passes the Ontario Line's maintenance and storage facility before turning south to continue west along the north side of Overlea Boulevard, to Thorncliffe Park station, just west of the western intersection between Thorncliffe Park Boulevard and Overlea Boulevard.

The Ontario Line Maintenance and Storage Facility

The Ontario Line Maintenance and Storage Facility will be located north and west of the Ontario line tracks, occupying a 17.5 hectare (43 acre) site north of Overlea Boulevard, between Beth Nealson Drive and the North Toronto rail corridor of Canadian Pacific Kansas City (CPKC). Tracks will descend from the elevated guideway to meet the facility's tracks at grade. The facility will feature storage for as many as 44 trains (as many as 220 cars), although the line will not open with nearly that many.

Thorncliffe Park Station

Thorncliffe Park will be a simple centre platform station with a pair of entrances, one on each side of Thorncliffe Park Boulevard, serving the dense surrounding community. There are no plans at present for a bus terminal, with transfers to surrounding surface transit handled at street level.

West of Thorncliffe Park station, the elevated guideway follows Overlea Boulevard before curving south over Millwood Road and across the main portion of the Don Valley built roughly parallel to and west of the Leaside Bridge. At the other end of the valley, the line will enter a tunnel beneath Minton Place before continuing south on Pape Avenue (bowing slightly to the west) to an underground station at Cosburn Avenue.

Cosburn Station

Cosburn station will have a central platform and be located beneath Cosburn Avenue just west of Pape Avenue. This was done to limit the amount of disruption to Pape Avenue itself, although it did mean that a row of houses and businesses were demolished. Station entrances would likely be placed on the north and south sides of Cosburn Avenue leading to a mezzanine level and fare gate facility, with additional escalators and elevators leading to the subway platform.

South of Cosburn station, the tunnel will shift back to Pape Avenue, passing a double crossover before curving slightly to the east side of Pape Avenue to reach Pape Station.

Pape Station

Pape Station will be a major interchange connecting the Ontario Line with Line 2 Bloor-Danforth, one of the key benefits that has driven proposals for this and similar lines throughout their history. Metrolinx estimates that the connection here will reduce rush-hour congestion at the Bloor-Yonge interchange by as much as 22 percent. The Ontario line will have a centre platform located beneath the Bloor-Danforth station, with escalators leading up to the westbound and eastbound platforms. An additional station entry will be built at Danforth Avenue leading directly to the Ontario Line platform.

South of Pape station, the tunnel would continue beneath Pape Avenue before curving southwest to run parallel to the Lakeshore GO Line and coming to the surface just north of Gerrard Street, in time to stop at Gerrard station

Gerrard Station.

Gerrard station will be located on an elevated structure separate from the Lakeshore GO Train corridor, above the intersection of Gerrard Street East and Carlaw Avenue, and will feature a single centre platform, one level above the street. The station's entrances will be located on the east side of Carlaw, north of Gerrard, and on the south side of Gerrard Street, next to the Gerrard Carlaw Parkette. The Gerrard Square shopping mall will be nearby, to the east of the station, but there are no plans for a direct connection. By 2025, the station's construction had already demolished a local strip mall, including a No Frills supermarket.

Travelling south from Gerrard station, the right-of-way moves onto Metrolinx's Lakeshore corridor, occupying the northwestern two tracks (Metrolinx had originally planned to have the Ontario line's tracks straddle the Lakeshore GO Train corridor. Before construction, the corridor had three tracks, with a fourth track added in 2025. The Ontario Line will expand this corridor to six tracks, with the expansion handled through fill and retaining walls. The tracks move southwest to Queen Street where they reach Riverside-Leslieville Station.

Riverside-Leslieville Station

This station, located on a railway bridge above Queen Street East, was originally named Leslieville, but renamed Riverside-Leslieville based on the Riverside neighbourhood on the west side of the tracks. This station will have a centre platform immediately above two street entrances, one on the north side of Queen Street beneath the bridge, and the second on the south side of Queen Street, on the west side of the railway embankment. Transfers to QUEEN and KINGSTON ROAD streetcars will be on the street.

To handle the station and the expansion of the rail corridor, Metrolinx began work to rebuild the railway bridge over Queen Street on June 5, 2023, raising it from its original 3.9 metres (13 feet) TO 5 meters (16 feet).

After Riverside-Leslieville, the Ontario line continues southwest along the Lakeshore GO Train corridor, curving west to East Harbour Station, located east of the Don River, on the south side of Eastern Avenue.

East Harbour Station

East Harbour station will be a major transfer point for the Ontario line, connecting Ontario line trains with Lakeshore East and Stouffville GO Trains in a combined station facility. The station would also be a major link to the Toronto Portlands Development, as well as nearby transit-oriented development, connecting with an extended Broadview Avenue and possible Broadview streetcar route. The station is located on old industrial lands, including the old Unilever soap factory.

The combined station will have six tracks within its structure, with the Ontario Line taking up the northernmost pair. A centre platform would sit between the Ontario Line tracks, while a pair of platforms would be between the next two pairs, each serving westbound and eastbound trains respectively. Passengers would connect between trains via a mezzanine level beneath the tracks, with exits onto Eastern Avenue. By offering direct connections between GO Trains and the Ontario line here and at Exhibition GO Station, Metrolinx hopes to reduce congestion at Union Station by as much as 14%, redirecting over 14,000 passengers from Union Station during peak hours.

After East Harbour station, the Ontario Line crosses the Don River on a new bridge and passes to the north of GO Transit's Don Yard before passing a double crossover and entering a tunnel just east of Cherry Street. The route continues underground, turning north under the east side of Berkeley Street before reaching Corktown Station near King Street.

Corktown Station

Corktown station will be an underground centre platform station located at the southeast corner of King Street East and Berkeley Street, with the main entrance located there. An emergency exit will allow passengers to leave the station onto Front Street, just east of Berkeley. Two city blocks bounded by Berkley, King and Parliament and the north side of Parliament Square Park were demolished to make way for tunnel launch shafts. As this is near the site of Upper Canada's first Parliament, Metrolinx brought in archeologists to monitor for and examine any artifacts discovered during construction.

Corktown station will be a site where tunnel boring machines are launched, with one heading north and west towards the downtown, while another heads south and east towards Don Yard.

North of Corktown station, the Ontario Line takes a broad turn west to run underground just north of Queen Street before reaching Moss Park Station at Sherbourne.

Moss Park Station

Moss Park station will be an underground centre platform station located on the southern edge of Moss Park, near the Moss Park Armoury, with the main entrance located at the northwest corner of Queen and Sherbourne. As of June 2025, plans for an emergency exit have not been finalized, but one will be built, by law. This station will feature a single central platform some distance underground and a mezzanine level. This station is expected to boast considerable walk-up ridership, located as it is within a fifteen minute walk from over 23,000 residents, and as many jobs.

The line continues underground, staying close or under Queen Street, before passing a double crossover east of Victoria Street and reaching Queen Station on the Line 1 Yonge-University subway line.

Queen Station

Queen Station will be a major interchange station connecting the Ontario Line with the Yonge subway, and also serving one of the busier intersections of the Downtown core, including the Eaton's Centre and the PATH network. Over 15,000 riders are expected during peak hours, making this the busiest station on the Ontario Line. Groundbreaking for this station was announced on May 28, 2025. The Ontario Line station will be built deep, requiring the excavation of over 100,000 cubic metres of dirt and rock, with its centre platform (40 metres below street level) passing below the Lower Queen "ghost station" roughed in just below the Yonge subway in the early 1950s in anticipation for a streetcar-subway that was never built. The Lower Queen ghost station will be used to help in the transferring between the two lines. With Queen Station already featuring seven entrances, no new entrances need to be built for the Ontario line.

Osgoode Station

Following Queen station, the line continues deep underground to a stop at Osgoode, providing a second connection with the Line 1 Yonge-University subway. The station will be deep underground, with its centre platform connecting to a mezzanine level beneath Osgoode's University line station. Construction will open two new entrances, one at the northeast corner of Queen and University, located on Osgoode Hall grounds, with a second at the southwest corner of Queen and Simcoe within the preserved facade of a bank building.

Queen-Spadina station

West of Osgoode station, the Ontario Line's bored tunnels continue beneath or near Queen Street before reaching Queen-Spadina station, located directly beneath the intersection of Queen Street West and Spadina Avenue. A mezzanine level will link the centre platform with station entrances built into preserved facades at the southeast and northeast corners of the intersection. Transfers with the 501 QUEEN and 510 SPADINA streetcars will be made on the street.

From here, the Ontario line curves southwest, reaching the King-Bathurst Station.

King-Bathurst Station

King-Bathurst Station will be located in an excavated cavern 40 metres below the intersection. Its centre platform will connect with a mezzanine level that links entrances located within preserved facades at the northeast and southeast corners of the King-Bathurst intersection. Connections with the 504 KING and 511 BATHURST streetcars will be made on the street.

Finally, the Ontario line's tunnel continues southwest to Strachan Avenue before turning west and coming to the surface on the north side of the Metrolinx Lakeshore GO Train corridor, just east of Exhibition Station.

Exhibition Station

Like East Harbour station, Exhibition Station on the Ontario line will share space with Exhibition GO Station on the Lakeshore West GO Train line. A shared concourse will facilitate connections between GO Trains and Ontario line trains. The station will also provide transfers to the 509 HARBOURFRONT and 511 BATHURST streetcars at Exhibition Loop. A new station entrance will be built north of the station onto Atlantic Avenue, serving Liberty Village.

Tail tracks to the west of Exhibition Station featuring a double crossover will allow Ontario line trains to turn back (meaning that the Ontario line will have separate arrival and departure platforms), as well as facilitating an extension to the west. Another double crossover will be located east of the station. The building at 153 Dufferin Street, opposite Dufferin Gate loop, is planned to be converted into a substation for the line.

Looking to the Future

By the summer of 2025, construction on the Ontario Line was well underway, with changes made or being made to the Lakeshore rail corridor at Exhibition GO Station and from the Don River to Gerrard. Caverns were already opening up at King-Bathurst station, and buildings demolished (some with facades preserved) at many station sites, including Queen-Spadina and Cosburn. As of July 2025, there were no indications of problems that would delay the line's proposed 2031 opening date, although only time will tell.

After 2031, a few ideas have been put forward for future expansions to the Ontario line. The tail tracks at Don Valley and Exhibition stations help protect those expansions. To the north, the line could run on an elevated guideway along the median of Don Mills Road to Sheppard Avenue, connecting to the Line 4 Sheppard Subway. A further extension from there could reach Steeles Avenue, reducing pressure on the Yonge subway as Line 1 reaches towards Richmond Hill, and providing its own access to eastern York Region.

West of Exhibition station, the Ontario line could take up old proposals to follow the railway tracks to Roncesvalles Avenue and turn north towards Dundas West or Keele Stations. From there, the line could continue northwest, possibly replacing the Union Pearson line up to Eglinton Avenue, or all the way to Pearson Airport. However, both the northern and western extensions are not a priority right now, and these extensions, if commissioned, likely won't see trains until the 2040s, if then.

Today (November 2025), work is proceeding quickly on the Ontario line, such that in its haste, Metrolinx is running into controversy with community groups and some powerful property owners. The urgency, however, is an illustration of how long this line has been coming. Proposals for a Queen Street subway go back to the early 20th century, and serious proposals for a Queen line materialized in the 1940s. The need for a Downtown Relief Line was clear to Metropolitan Toronto planners in the early 1980s when it established its Network 2011 proposal, and since then the need has become more acute. Not only is Bloor-Yonge station pushing past its capacity, even with its planned renovation, capacity issues need addressing at Union Station, which is one reason why the line has been redesigned to serve Exhibition and East Harbour stations.

For this reason, this line which will have been over 120 years in the making once it opens promises to transform not only downtown Toronto, but the whole Greater Toronto Area.

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Ontario Line Image Archive

	A map showing the track arrangement of the planned Ontario Line Maintenance and Storage Facility in relation to Thorncliffe Park Station. This image is courtesy of Metrolinx, issued on February 1, 2022.
	A render of the Ontario Line Queen Station platform, archived from the Metrolinx website.
	On June 22, 2025, Damian Baranowski took this photo of the structure set up to preserve the facade of the old bank building on the northeast corner of the Queen-Spadina intersection. The building will be repurposed into an entrance into Queen-Spadina station on the Ontario Line.

References

• Chaudhary, Kunal. "Who's Building This Thing? Metrolinx Is Turning to International Conglomerates to Build Its New Subway." Spacing, 2023, pp. 36-37.

• Chen, Rachel. "Showdowns on the Line: From First Station to Last, This Transit Project Is Stirring Controversy." Spacing, 2023, pp. 32-33.

• Munro, Steve. "TTC Service Changes Effective Sunday, September 3, 2023 (Preliminary)." Steve Munro, 29 Aug. 2023, stevemunro.ca/2023/08/26/ttc-service-changes-effective-sunday-september-3-2023-preliminary/.

• Munro, Steve. "What's the Difference? How the Ontario Line Compares to Toronto's Existing Subways." Spacing, 2023, pp. 30-31.

• "Ontario Line: World of Role Models Available for Subway Planners." Metrolinx, 17 Sept. 2019, www.metrolinx.com/en/discover/ontario-line:-world-of-role-models-available-for-subway-planners.

• "Province Breaks Ground on Ontario Line." Ontario Newsroom, Government of Ontario, 27 Mar. 2022, news.ontario.ca/en/release/1001832/province-breaks-ground-on-ontario-line.

• "Province Breaks Ground on Ontario Line's Queen Station." Ontario Newsroom, Province of Ontario, 28 May 2025, news.ontario.ca/en/release/1005963/province-breaks-ground-on-ontario-lines-queen-station.

• Ramos, Daniel. "Metrolinx Reveals Names of Ontario Line Tunnel Boring ..." Toronto Today, 20 Nov. 2025, www.torontotoday.ca/local/transportation-infrastructure/metrolinx-names-ontario-line-tunnel-boring-machines-11517426.

• Richardson, Courtney. "2025: The Year of Digging for the Ontario Line?." Metrolinx, 28 Jan. 2025, www.metrolinx.com/en/discover/2025-the-year-of-digging-for-the-ontario-line.

• Spurr, Ben. "How Ford's Ontario Line plan came together in just three months - with secrecy, a shifting route and a consultant." Toronto Star, 15 Feb. 2020, https://www.thestar.com/news/gta/2020/02/15/how-fords-ontario-line-plan-came-together-in-just-three-months-with-secrecy-a-shifting-route-and-a-consultant.html

• "TTC 501 Queen Streetcar Reroutes to Support Ontario Line Work." Metrolinx, 6 Nov. 2024, www.metrolinx.com/en/discover/ttc-501-queen-streetcar-reroutes-to-support-ontario-line-work.

• Wilbur, Sara. "Queen Street Diversion Starts May 1 for Ontario Line Work." Metrolinx, Metrolinx, 11 Apr. 2023, www.metrolinx.com/en/discover/queen-street-diversion-starts-may-1-for-ontario-line-work.