Toronto Ontario Line 3 | ?m | ?s | Metrolinx

[Sunnyside]

To be fair, the city planners had the foresight to build the Don Valley crossing for a future subway line ~40 years in advance (1918 completion of the Prince Edward Viaduct vs. 1958ish for decision to build Line 2). This would have been the most complicated part of the project.

I cannot recall any foresight on a comparable scale done by transit planners since.

The 407 Transit right-of-way, easily. And before it, the Finch hydro corridor. Just waiting for us to use it properly…