Yonge Subway Headway Study 1988 (Part 6)

I am inserting a little sidebar into the discussion because my archives yielded up an exhibit not included in the TTC’s report.

Exhibit 2.1.1: 2011 Forecast For Base Case Network

This is the demand analysis shown in Chapter 2 which establishes the “need” for additional capacity on the Yonge line, specfically at Bloor-Yonge Station.

Network 2011 Demand Analysis

This is the companion chart from the Network 2011 study showing the projected demand on the rapid transit network with the addition of lines on Eglinton West, Sheppard, the DRL and the Spadina/Harbourfront line.

These two charts appear side by side in the Network 2011 study, but only the first one was included in the Improved Headway Study.

The DRL diverts a good chunk of traffic off of the Yonge line below Bloor, although this is partly backfilled by new riding pouring in at the top of the line. (Other studies had different versions of this line including routes that went further north.)

The projected demand on the Spadina line, 7,500 per hour, was rather high considering it was to be a surface operation crossing many streets. Oddly enough, only the Harbourfront portion was built initially, and we waited until 1997 for the Spadina streetcar.

I don’t intend this to be a definitive example of a demand model (I don’t think “definitive” is a word one can use in that context anyhow), but it points out how the importance of the DRL was recognized over 20 years ago. Indeed, in the Network 2011 plan, it was the second priority for construction with 1st place going to a Sheppard line only as far east as Victoria Park.

Yonge Subway Headway Study 1988 (Part 5)

In this section, we begin Chapter 4 of the study with a description of the centre platform option at Bloor-Yonge Station.

Some of the work needed for this scheme was built during construction of 33 Bloor Street East and the Toronto Parking Authority lot between Hayden and Charles Streets.  The TTC took advantage of the subway structure being uncovered to widen the station and replace the centre columns with a roof spanning both platforms and tracks.  As you can see from visiting the station, this work ends at the northern third of the station because this is physically inside the structure of The Bay.

The section on construction feasibility describes what is necessary to continue this layout further north and it involves, among other things, closing the Bay’s concourse during construction.  That entire passage is almost surreal because it details problem after problem with the construction, but forges bravely onward.  There’s also the small matter of closing Bloor-Yonge Station because the existing platforms must be removed before the tracks can be relocated.

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Yonge Subway Headway Study 1988 (Part 4)

This installment completes Chapter 3 of the study with the evaluation of alternative signalling strategies.  The recommented alternative is Automatic Train Control, no surprise there, based on the premise that it provides the maximum benefit versus the expenditure.  Underlying this, however, is the goal of a 90-second headway and the increasing challenges to subway operations as the headway drops.  ATC is treated as a means to achieve this dubious goal rather than a worthwhile move in its own right.

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Yonge Subway Headway Study 1988 (Part 3)

This section presents considerations for the vehicle fleet and yards required to house these cars.  An important consideration for any decrease in headway is that the number of trains in service goes up.  This generates added capital and operating costs for an expenditure that addresses only peak period demand.

A proper comparison of lines would look at what happens if the fleet is expanded (regardless of the technology) elsewhere so that new off-peak service is available in a corridor that does not now have rapid transit.

As we will see later, the additional vehicles are a substantial portion of the total project cost for peak headway improvements on an existing line.

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