It’s definitely feasible. And IMO it’s much more optimal to connect a station along the Don Branch to Broadview than it would be to connect the Richmond Hill line to Castle Frank – both because of the smaller distance, but also the smaller elevation. Another good point is that the City owns a large and well-located TDSB property between Broadview Stn and the valley which could easily be redeveloped with a pedestrian connection below. These are a couple of maps I made awhile back to give an idea of the potential:
I made a post in another forum, which is useful to repost here:
____________
Now that the RER electricification plan is announced, and it excludes electricification of Richmond Hill line, I propose the following idea as a useful transit line that may be cheaper than adding new subways:
Pros:
- More corridor space to double-track than Richmond Hill (can even triple-track small sections for passing)
- Two way frequent all day electricified service (15min or better)
- Metrolinx owns Don Branch now
Proposed stations:
1. Eglinton Station (ECLRT interchange, Ontario Science Centre)
2. Millwood St Station (large residential neighborhood to west)
3. Danforth Station (interchange with TTC Broadview subway, Greektown)
4. Gerrard St Station (interchange with TTC Gerrard streetcar, Bridgepoint Hospital, Riverdale ped bridge)
5. Queen St Station (interchange with TTC Queen streetcar, Regent Park)
6. Union
Requirements:
- Refurbishing and adding extra trackage
- Redoing the big bridge (1100 feet) to accomodate extra track
- There's already double-tracking to north of Gerrard, south of Danforth. Don Branch and Richmond Hill can share this.
- Add a small bit of track to the south of Leaside trainyard (between Eglinton and Millwood), may require expropriation of one small office/utility building, physically grade separated from freight. Delicate negotiations needed.
- Timeline would theoretically be "the next 10 year plan" (2025-2034)
Engineering Challenge Note:
- Flooding on low tracks. Need to raise flood-prone tracks first. (biggie)
- Hillside Escalators (like Ontario Science Centre), e.g. Danforth station connecting Playter Gardens to a Don Valley overpass to station on west edge of Don Branch under Bloor-Danforth. Broadview TTC is only ~200m horizontal separation, not too much more than the 150m TTC Spadina hallway, and escalator will reduce walking compared to that. Ped tunneling may be an engineering challenge.
- Electric substation potentially in way of one of the stations (is there room? Reaching near end-of-life? Relocation opportunity? RER electricification opportunity?)
- Union capacity (offpeak won't be a problem, but peak might be problematic in 15 years)
This line may have large amount of community pressure, due to scenery disruption, but would be greatly preferable over widening the Don Valley Parkway. Once Toronto falls in love with RER convenience, community opposition might loosen a bit by the mid-2020s, especially if Don Valley Parkway gets worse and part of Gardiner is planned to be demolished.
As we know, one single GOtrain carries one full hour of freeway lane traffic (2000 cars per hour) -- don't underestimate the need for this train in Toronto, circa 2031. A single track can move far more people during peak than an 8-lane freeway! A pair of railroad tracks, properly signalled, with some extra passing track, can push eight GOtrains per hour in each direction, moves more people than the whole width 16-lane of 401 combined! Europe has pulled that off, with even-more-frequent trains in some corridors (e.g. Paris RER 3-minute headways). In addition to population growth through 2031, combined with demolishing parts of the Gardiner, we will need RER in the Don Valley (on either line).