TTC Rediscovers the Downtown Relief Line (Update 4)

Update 4 October 21, 2012 at 8:30 pm:

It’s intriguing to look back at coverage of the DRL the last time this was a major issue.  Mike Filey passed along a clipping from the Star from December 2, 1982 that makes interesting reading.  My comments are at the end in Postscript 2.

Update 3 October 20, 2012 at 3:20 pm:

A postscript has been added discussing the various demand simulations as a group rather than individually.  Charts of total demand southbound from Bloor Station as well as pedestrian activity at Bloor-Yonge are provided to consolidate information from several exhibits in the background paper.

Update 2 October 19, 2012 at 11:00 am:

This article has been reformatted to merge additional information from the background study as well as illustrations into the text.

At its meeting on October 24, 2012, the TTC will consider a report on the Downtown Rapid Transit Expansion Study.  The full background paper is also available on the TTC’s website.

A study by the City of Toronto and TTC, including consultations with Metrolinx, concludes that transit demand to the core by 2031 will grow at a rate that exceeds the capacity of all of the current and planned transit facilities.  Ridership will be 51% higher than today.  The residential population south of College from Bathurst to Parliament will grow by 83%, and employment by 28%.

Capacity is an issue today as Table A-1 in the background paper shows.  Several corridors into downtown are already operating over their design capacity.  This is particularly the case on GO where the target is to have few standees, and there is more room for additional passengers in the design capacity than on the TTC subway services.

Table A-2 shows the projections for 2031.  All of the shortfalls are on GO, but the TTC lines are close to saturation.  This presumes a considerable increase in the capacity of various lines.  For example, the YUS goes from a design capacity of 26,000 to 38,000 passengers per hour (pphpd), an increase of 46% which may not actually be achievable.  Similarly, the BD line goes to 33,000 pphpd, an increase of 27%.

Exhibit 1-10 shows the components of projected capacity increase including 36% from running trains closer together.  As discussed at some length on this site previously, the constraints on headways arise at terminal stations.  A 36% increase in trains/hour implies a headway of about 100 seconds as compared with 140 today.  This cannot be achieved with existing terminal track geometry, not to mention the leisurely crew practices at terminals.

On the GO lines, the projected capacity on Lakeshore West doubles, and smaller increases are seen on other routes.  It is worth noting that the projected capacity of the north-south corridors to Stouffville, Richmond Hill and Barrie are nowhere near the level of service implied by The Big Move, probably because these lines are not targets for early electrification.  This contributes to the capacity shortfall in the northern sector.  Recommendation 1 of the study includes encouragement that Metrolinx review the possibility of increased capacity in those three corridors.

The full list of lines included in the modelled network can be found in the background study at section 1.2.1.

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