A Few Myths About Subway Capacity (Updated)

Updated October 18 at 10:15 am: A few comments about system reliability during bad weather have been added as a postscript to this article.

In a recent post, I wrote about the TTC’s Capital Budget and the projects that are creeping into view as the true cost of adding capacity to the subway becomes evident.

Once upon a time, the TTC was really worried about the capacity of Bloor-Yonge Station, and came up with a scheme to add a third central platform on the upper (Yonge) level, and possibly a second, eastbound platform on the lower (Bloor) level.  Interest in this project faded with the dwindling riding of the mid-1990s, but it never completely vanished.  Plans such as a Richmond Hill extension raised concerns about YUS capacity even before recent ridership growth took back the “surplus” capacity available for many years to hide the problem.

Independently of the third platform proposal, the TTC came up with a plan to add to the number of trains on the line.  If only they could convert to automatic train control (ATC), they could decrease the headway of trains and add to the line’s capacity.  In practice, what happened was that the TTC had to replace the existing, worn out signal system anyhow, but really wanted other governments to buy into the project.  At that point, ATC’s justification became not only the rejuvenation of the subway (a maintenance project), but a way to add capacity at lower cost than building a new line.

Of course, the trains the TTC was running, the H-series cars and the newer T1 fleet, are not equipped for ATC.  A retrofit of the T1 fleet is possible but expensive, and this drives a “need” for a completely new fleet simply to make use of ATC on the Yonge line.  In earlier fleet plans, the TTC treated the entire system as one pool and simply counted trains regardless of which type they might be.  Now, however, they need a “YUS” fleet that can run ATC and a “BD” fleet that will run with conventional manual controls.  (It is unclear what will happen if a BD train finds its way onto YUS trackage, say, for a diversion.)

With the recent, overdue arrival of the first TR train in Toronto, there were bold statements by the Mayor no less (although he was just parroting the TTC) about how these new cars would allow a 40% increase in subway capacity.  Well, yes, maybe, but there’s a catch.  Several catches, in fact.

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