I for the life of me do not understand the rationale for Midtown GO, other than the opportunity of an existing railway - Summerhill is not a major node. GO Rail along the future 407 Transitway seems like a bunch stronger win for regional connectivity.
But if the CP line is going to be used, could it be tied into the existing Richmond Hill line tracks around Millwood, adding connectivity to downtown for very transit-sparse areas of Scarborough? (Thinking stops at Lawrence, Ellesmere, Sheppard, Malvern)
Well, yes, i'm not sure anyone would be talking about the Midtown GO line if there was no railway at all. The hubbub about it is primarily that the benefit/cost is incredibly high for a transit project
- The rail is indeed already there
- It has room for more rail, as it already did-- a split corridor a la LE with freight and passenger totally separated is possible
- Downtown / downtown adjacent (depending on who you ask lol)
- Though everyone focuses on connections to 1, there's no reason we couldn't extend it eastwards into Scarborough and even into Pickering with a single tie-in onto the CN tracks where the CP/CN cross at Plug Hat Rd (Though that last stretch will probably be much harder due to track limitations)
- Has connection opportunities for the LW, MI, 2, 1, ~5, OL, ~ST, 4 East ext., SSE, LE
- Bypasses Union, which is very good for both system stability and speed
I suspect it's probably going to start with a relatively barebones schedule, but with some relatively easy improvements compared to every other GO line, it really has the opportunity to become a vital 15 minute or lower E/W corridor that connects both the city within and the GTA as a whole, especially with a Lakeshore-Midtown config available. Assuming a 60kmh rolling average, a trip from STC -> Kipling could take just 30m, whereas STC -> Kipling via SSE will probably take upwards of an hour.
I have previously drawn up theoretical maps of a 407 regional train route, and it is one that I'd love to see built. It would absolutely be great for regional connectivity outside of Toronto. You are also talking a LOT of time and a LOT of money.