Here's what happened with Toronto's Scarborough Subway Extension in 2025
The Scarborough Subway Extension (SSE) will eventually extend the TTC's Line 2 Bloor-Danforth another 7.8 kilometres, adding three new stations to Toronto's second-busiest transit route.
The over $10 billion route extension (its cost more than doubled in 2025) has been under construction since 2021, and made significant headway in the last year, albeit with some major challenges along the way.
SSE tunnelling, which began in January 2023, is being carried out with the largest tunnel boring machine (TBM) ever used on a Canadian transit project. Unlike the twin bored tunnels carved for other modern lines and extensions, the extended Line 2's trains will run in a single cavernous tunnel that is substantially wider than the local norms, with a diameter of 10.7 metres.
Dubbed 'Diggy Scardust' in a hilarious nod to David Bowie's Ziggy Stardust persona and the project's location in Scarborough, the enormous TBM is almost halfway through its almost seven-kilometre journey to etch out the line's underground section.
Tunnelling progress, as impressive as it is, was hampered from 2024 into mid-2025 when the mighty Diggy Scardust was lodged beneath Highway 401, attributed to soil conditions. After rushed repairs, tunnelling resumed, though the delay is expected to push back the line's previously announced 2030 opening target.
Despite challenges underground, work on the first station — Scarborough Centre — officially kicked off back in August.
Work is also racing along at other station sites, like ancillary buildings taking shape at the site of Kennedy Station.
Other major SSE news in 2025 included Metrolinx's move to spare a futuristic pedestrian crossing serving the defunct Scarborough Centre station on the 2023-shuttered Line 3 Scarborough RT.
While the Scarborough RT's closure and the long-term construction for its replacement subway extension have made getting around Scarborough a pain, the TTC announced in mid-December that it would open its Scarborough Busway in 2026, a year ahead of schedule.
Metrolinx
