Debate on the merits of the Scarborough Subway Extension

[Rainforest]

The ideal solution WAS grade-separating Eglinton in Scarborough and interlining the Scarborough LRT with Eglinton.

There has been much discussion on why it is very difficult to elevate the B-D line (mostly it takes 750m ot 1000m to switch a subway from underground to elevated, and all cross streets, entrances, etc. are blocked for this length).

The compromise to all of the above is a mostly elevated ICTS/SkyTrain line going from STC with no transfers all the way downtown. (yes - I found an opportunity to raise this again)

View attachment 131028

This plan has it merits, but it would cost a lot.

The underground downtown section of the blue line alone (from Don Valley to the west end) is likely to cost more than the whole SSE, because of the need to deal with utilities and the PATH.

The rest of the blue line would presumably run either on surface (in the natural corridors or Hydro corridors) or elevated; that's cheaper per km than in a tunnel, but the whole 25 km would cost quite a bit, too.

 

[Streety McCarface]

This plan has it merits, but it would cost a lot.

The underground downtown section of the blue line alone (from Don Valley to the west end) is likely to cost more than the whole SSE, because of the need to deal with utilities and the PATH.

The rest of the blue line would presumably run either on surface (in the natural corridors or Hydro corridors) or elevated; that's cheaper per km than in a tunnel, but the whole 25 km would cost quite a bit, too.

Radical and potentially stupid idea: replace the Gardiner and DVP with an elevated Heavy Rail Line like in Chicago.

 

[TheTigerMaster]

The ideal solution WAS grade-separating Eglinton in Scarborough and interlining the Scarborough LRT with Eglinton.

There has been much discussion on why it is very difficult to elevate the B-D line (mostly it takes 750m ot 1000m to switch a subway from underground to elevated, and all cross streets, entrances, etc. are blocked for this length).

The compromise to all of the above is a mostly elevated ICTS/SkyTrain line going from STC with no transfers all the way downtown. (yes - I found an opportunity to raise this again)

View attachment 131028

Why the route duplication with the Relief Line?

 

[WislaHD]

Why the route duplication with the Relief Line?

I think to take advantage of the available hydro corridor.

While on the map they are geographically near routes, this and the Relief Line would be serving different commuter markets. BurlOak's line would be serving residents deep into Scarborough.

Unless you are referring to the downtown segment.

 

[Rainforest]

Radical and potentially stupid idea: replace the Gardiner and DVP with an elevated Heavy Rail Line like in Chicago.

Radical, but not stupid.

You wouldn't even need to replace the whole Gardiner or DVP. Re-purposing two lanes of DVP (out of today's 6) for the Relief line could make its construction a lot cheaper.

However, connection to Line 2 would be a challenge if the Relief line runs in DVP corridor. It would probably have to swing out of it in order to have a viable interchange with Line 2.

 

[BurlOak]

I think to take advantage of the available hydro corridor.

While on the map they are geographically near routes, this and the Relief Line would be serving different commuter markets. BurlOak's line would be serving residents deep into Scarborough.

Unless you are referring to the downtown segment.

Yes. Basically, the "Scarborough line" has the basic job of doing what the B-D extension does, but better, and as cheap as possible.

• The 2 serve different area. DRL goes to Seneca and the Don Mills corridor, while this "Scarborough Line" cuts diagonally through Scarborough to serve mostly Malvern, Centennial, and STC.
• They sort of share a common portion through Flemingdon and Thorncliffe, but this is really only about a 2km segment. It provides an oportunity for an interchange (connectivity is always important) and it also allows the 2 to share a common train yard near Overlea and Millwood (near the waste treatment plant).
• Farther south, DRL serves Pape and Greek Village, Riverside, while the "Scarborough Line" is really looking for the cheapest route downtown, and sort of serves Regent Park.
• Through downtown, I think there is enough ridership that a route along Queen and 1 along Wellington are far enough apart. They also criss-cross here as well, with an interchange station at/near Queen/River/Eastern

 

[TheTigerMaster]

I think to take advantage of the available hydro corridor.

While on the map they are geographically near routes, this and the Relief Line would be serving different commuter markets. BurlOak's line would be serving residents deep into Scarborough.

Unless you are referring to the downtown segment.

Yup I was taking about the downtown

 

[BurlOak]

Besides the idea of a separate line from Scarborough to downtown, the other option for SSE is the station at Lawrence.

I saw this image from the FWLRT thread that reminded me of this.


Ignore the subway and look at the LRT portion to the right. This LRT station is directly under the Finch/Keele intersection. By scaling, the track are located about 6m below grade, with a passageway under it. This shows the solution to a possible McCowan/Lawrence station.

Locate the tracks about 6 to 8m below grade as they cross Lawrence. This allows the utilities from Lawrence to pass over the station box. A little north, the tracks would rise to being about 5m below grade, with traffic running directly on the subway structure. The "Mezzanine" for the station would be below the platform, much like the walkway. This "mezzanine" is only needed at the station, so why build the track an extra 5 or more meters in depth (and requiring the use of TBM) for its entire length, when you can instead build a shallow linear structure (using cut-and-cover).

 

[Streety McCarface]

Besides the idea of a separate line from Scarborough to downtown, the other option for SSE is the station at Lawrence.

I saw this image from the FWLRT thread that reminded me of this.

View attachment 131292
Ignore the subway and look at the LRT portion to the right. This LRT station is directly under the Finch/Keele intersection. By scaling, the track are located about 6m below grade, with a passageway under it. This shows the solution to a possible McCowan/Lawrence station.

Locate the tracks about 6 to 8m below grade as they cross Lawrence. This allows the utilities from Lawrence to pass over the station box. A little north, the tracks would rise to being about 5m below grade, with traffic running directly on the subway structure. The "Mezzanine" for the station would be below the platform, much like the walkway. This "mezzanine" is only needed at the station, so why build the track an extra 5 or more meters in depth (and requiring the use of TBM) for its entire length, when you can instead build a shallow linear structure (using cut-and-cover).

Vibration, noise, surface disruption, pollution (from flange grinding), etc. Quite frankly, if they built a cut and cover subway line right next to my place, I wouldn't care about any of those things because the benefit of available transit greatly offsets the small noise and vibration. However, suburbanites tend to not be in support of such moves. People want it out of site and out of mind.

 

[speedkar9]

Why does everyone believe all commuters want to only go downtown?

 

[lead82]

Why does everyone believe all commuters want to only go downtown?

Because that’s where choice committees want to go and that’s the only voice politicians hear. That’s why GO RER is popular even though it really only helps to support downtown commuters in the financial district. Politicians don’t care about local transit.

 

[TheTigerMaster]

Why does everyone believe all commuters want to only go downtown?

Because that’s where choice committees want to go and that’s the only voice politicians hear. That’s why GO RER is popular even though it really only helps to support downtown commuters in the financial district. Politicians don’t care about local transit.

Telling voters they're getting 10% more bus service isn't as sexy as a new subway station.

A thing that has always humoured me about Metrolinx literature is their enormous overemphasis on regional travel. Based on the space they dedicate to it in their literature, you'd think that regional trips, and GO Transit especially, make up the bulk of transit ridership in the GTHA, when in reality GO Transit doesn't even carry 10% of GTHA transit trips.

 

[BurlOak]

Why does everyone believe all commuters want to only go downtown?

Because bus is generally the best way to serve local. Also, any travel with greater travel distance, where a real difference in travel time is needed, requires grade-separation.

 

[amnesiajune]

That’s why GO RER is popular even though it really only helps to support downtown commuters in the financial district.

This is all kinds of wrong. If there's one group of people that doesn't benefit from Go RER, it's the ones who do work in the financial district. Go Transit is already awesome for them, and adding more stations is gonna slow down their commutes. The people who benefit from RER are the ones who commute out of the city and into the suburbs.

 

[amnesiajune]

A thing that has always humoured me about Metrolinx literature is their enormous overemphasis on regional travel. Based on the space they dedicate to it in their literature, you'd think that regional trips, and GO Transit especially, make up the bulk of transit ridership in the GTHA, when in reality GO Transit doesn't even carry 10% of GTHA transit trips.

Percentage of transit trips is a bad metric - if lots of people are using transit, that's because the transit system they use is already working well. What matters is the percentage of all trips that happen on public transit. By this metric, regional commutes - more specifically, commutes from the 416 to the 905 - are by far the worst-served by public transit. Even the 905's worst bus routes have more frequent service than Go Transit's AM outbound and PM inbound buses.