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.

3 thoughts on “Yonge Subway Headway Study 1988 (Part 6)

  1. That seems to say 18,680 per hour on the Eglinton West RT into the terminus. he-hem – that is a lot larger than the 5,400 now projected for the Eglinton LRT.

    Steve: That’s one of several examples of how the TTC’s omission of GO Transit from the network forces the model to assign all trips to whatever it’s told about. In this case, the demand from the west flows via Eglinton because it has no place else to go.

    What I am trying to illustrate is how decisions are made based on a set of flawed premises, and we live with the effects for decades afterward.

    On the Spadina streetcar, models of the time assumed a two-minute headway of 150-foot long trains (two ALRVs) with a capacity of about 8K per hour. You may have noticed that it would be difficult to fit two of these trains into Spadina Station loop for concurrent loading and unloading, and I won’t say anything about that ridiculous loop at Union.

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  2. Do we have any current PPDPH numbers for the existing lines?

    Steve: No, although the fact that the TTC has no planned any peak period subway service improvements means that (a) they can’t fit more trains on the line or (b) have not exceeded the design capacity of the existing service or (c) they can’t afford to run more service.

    (a) Is not valid because they have run closer headways in the past, although to do so requires tightening up the running time to reduce queueing problems at terminals.

    (b) Probably valid measured over the peak hour, but not the peak quarter-hour. The smallest delay creates quite a backlog of demand on the platform westbound at Broadview in the AM peak.

    (c) A service change like this would probably show up explicitly in the budget, and nothing was planned for 2008. I have not reviewed the details of the 2009 budget yet to see what might be in the cards.

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  3. Oh – the loop at Union – makes me feel like I’m a cattle yard ready for sorting and whatever comes next.

    For the record, I’d be interested in knowing what the actual figure is for the Spadina LRT? I notice is isn’t on the service improvement list you posted.

    Steve: You won’t see any AM peak streetcar service improvements because there are no spare streetcars. How they will operate the system once the 512 St. Clair comes fully back in operation is a mystery. TTC has been asked repeatedly to provide vehicle availability data, but nothing has been published.

    This is the dark side to an otherwise rosy news story about service improvements.

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