A booming transit expansion is currently underway in the Toronto area, with a handful of massive projects forging ahead, albeit at quite disparate paces.

The Ontario Line subway has been hitting milestone after milestone on its rapid track to completion, while progress on the Crosstown Eglinton LRT — which will live in infamy for its troublesome, drawn-out construction process — continues to hit snags more than four years after its projected public premiere.

But, the Crosstown unfortunately isn't the only local route that's become plagued with difficulties on the way to opening.

Toronto is already having drama with two transit lines that aren't even built yethttps://t.co/19KzHgKZpS

— blogTO (@blogTO) August 12, 2024

Legal issues are holding up Toronto's nearly-complete Finch West LRT, there is doubt that Metrolinx will be able to meet creditor deadlines for Mississauga's Hazel McCallion Line, and now, soil conditions are apparently impacting tunnelling work on the Scarborough Subway Extension, among other issues.

The eastern pocket of the city has been making do with replacement buses since the demise of the Line 3 Scarborough RT in summer 2023, with locals calling for service improvements while they await the completion of the three-stop subterranean extension, slated to open in 2030.

But, crews have recently "encountered soil conditions different than expected that have hampered the progress of the tunnel boring machine," Metrolinx executives shared in a recent Board of Directors meeting, though they added that the project is "progressing reasonably well."

Transit users deliver oversized 'invoice' to Toronto for lost time on TTC https://t.co/oKo6lz7ZkX

— blogTO (@blogTO) January 19, 2024

"We have worked with [construction company] Strabag on a technical solution and a schedule solution, and we hope to be giving more updates on that in the near future," they said of the issue.

The unforeseen delay comes after more than one kilometre of digging by the monstrous piece of machinery, nicknamed Diggy Scardust, which began its journey carving the future line's 10.7-metre wide, 7.8 km-long path in January 2023.

Though Strabag has extensive tunnelling expertise, it is hard not to worry considering the track record of some of Metrolinx's other projects on the go, especially given the amount of tunnel outstanding and the very little information being made available about details of the soil conditions and how significantly they could inhibit digging.

Completely understandable. Ground geotechnical conditions are not linear or consistent. They take samples and conduct tests at points at a finite number of boreholes but then must basically extrapolate between those across the entire linear route. Ground is too complex.

— Jack Tattersall  (@JackTattTran) November 30, 2024

In its latest update on October 3, the transit agency did reveal that piling had just wrapped up north of Kennedy GO station to prep for satellite buildings associated with the line, while work on one of the key ventilation fan plants pushes ahead, along with "service upgrades."