There are a couple of things to note here, before moving to the North Toronto line thread
1) The North Toronto corridor west of Mount Pleasant is most certainly wide enough to house both a 2ish track CP freight line and a 2ish track transit corridor (be it conventional GO heavy rail pax, or some other flavour of transit). CP no longer switches many sidings along this route so would not be seriously impacted by such a proposal.
However.....
2) Similar to LSE east of the Don, and ML on the Kitchener line thru the Brock-Lansdowne area..... building a transit corridor would likely trigger a desire to rework all the aging road underpasses, and CPKC would no doubt pass this cost to government. So costs and impacts would be commensurate to what ML is shouldering for the Ontario line. Certainly doable.... but at a major cost. Can we make the case for giving this funding priority over other potentil corridors ?
3) I can't agree with earlier posts that suggest that VIA would have difficulty reactivating the Don Branch. As much as we hope to reinvigorate the Don Valley, a railway line that runs a stone's throw away from the DVP cannot be described as environmentally intrusive. HSR will have no difficulty qualifying this line for an important (electric) intercity passenger line. It's a short stretch of track, and the major bridge, while in need of repair, is fundamentally sound.
4) While people look at the lovely former North Toronto station and romanticize about it reverting to a railway station.... the reality of land development already in progress in the area of the station, and the cost of building a terminal at Yonge, or converting the heritage structure and surrounding infrastructure (think platforms and layover infra) is not economically viable or simple in an engineering sense. Possibly a new station might be built, especially closer to the Dupont subway (as opposed to Yonge-Summerhill) but I question the desire to add ridership to the already stressed Yonge transit line.
5) Add the cost of buying this line from CPKC and the undesirability of splitting either a GO or an intercity service away from the Union hub
6) The closely parallel TTC Line 2 is not yet running at capacity
7) While the corridor may have width, east of Yonge there would be a need for some new bridges.... very, very big bridges....
So to my mind, while transit might come to this route in about 2060, I can't see either the need nor the political interest in building it sooner than that. By then I will be long gone.... not my problem ;-)
- Paul