Yonge Capacity Issues

The Yonge Street subway has been the backbone of the Toronto transit system since its opening in 195419.  In the 1980’s, ridership on the Yonge subway hit an all-time high, peaking at approximately 30,000 passengers per hour before declining to 20,400 in 1996-1997. Since then, ridership has returned to 1980’s levels, which is within the practical capacity of the current system, which the TTC estimates to be between 29,700 and 30,800 passengers per hour172.

Before the ridership decline of the 1990’s, the plan resulting from the 1980’s ridership figures was the first official incarnation of the Downtown Relief Line, a plan to take pressure off of the Yonge subway by allowing passengers traveling from the eastern side of the city a method of getting downtown without needing to transfer at Bloor/Yonge. When it was first planned, the estimated cost was $565 million165. Though heavily debated in council, the project was forgotten about once the necessity for such a line declined as a result of ridership losses.

A quarter century later, and we’re back to the same problem. This time, however, officials seem to be relegating the Downtown Relief Line as “[…] a last resort to address capacity issues into the downtown core”172. Instead, they propose a series of smaller improvements to increase the capacity of the Yonge line.
These improvements are as follows:

  • Conversion of the line to “Toronto Rocket” subway cars
  • Automatic Train Control/Operation
  • Diversion of riders to the Spadina subway
  • Adding a car to the subway trains
  • Reconstruction of Bloor-Yonge Station

The Toronto Rocket Subway Cars

An analysis of these options shows that they will not be enough on their own to address the passenger demand of the Yonge subway after the construction of the Yonge North extension.  Metrolinx estimates that by 2031, assuming the Yonge extension is constructed, 42,000 passengers per hour (pph) will be using the subway during peak hours17. This estimate takes into account the diversionary effects of the Spadina subway extension, meaning that factor cannot be used to account for increased capacity on the Yonge subway.

If Metrolinx is correct in their estimate, by 2031 the TTC will need to increase capacity on the Yonge line by approximately 12,000 pph.  The new “Toronto Rocket” subway cars will increase capacity by 3,200 pph compared to the current T1 cars operating the route171. This brings the capacity of the Yonge line from approximately 30,000 to 33,200.

Automatic Train Control will allow trains to run in closer intervals than they are currently scheduled, resulting in a 36% increase in capacity due to the larger number of trains operating per hour172. This pushes capacity to approximately 45,000 pph.

Though adding a 7th car to subway trains would increase capacity by 10-17%, the TTC notes it to be a “complex engineering, technical, and operational issue”172.  Lengthening the cars would require altering the tunnels, and it seems as though this potential capacity improvement is justifiably seen as not worth the potential investment, as in the same report that considers the Downtown Relief Line to be a “last resort”, longer trains is not listed as one of the conditions to be met to increase capacity on the Yonge line prior to a Downtown Relief Line needing to be built172.

The final piece of the puzzle to allow greater throughput on the Yonge subway is the reconstruction of Bloor-Yonge station to accommodate more passengers. This would not push the capacity of the line beyond the limits of the trains; rather it wouldallow them to run at this higher capacity by reducing the dwell time at Bloor-Yonge station and allowing trains to flow through at the increased headways without delays.

45,000 pph thus becomes the future capacity of the Yonge subway line, 50% higher than its current capacity. This number may even be optimistic, as Karl Junkin did a detailed analysis of the TTC’s figures regarding capacity improvement and found them to be exaggerated, putting the numbers himself at 37,714 pph without a seventh car added93. Steve Munro also interprets these figures to be higher than what is actually feasible. Using the TTC’s numbers, it may seem like a significant capacity increase, but even those potentially inflated numbers only allow a buffer of 3,000 pph above projected ridership demand.

Is it possible that demand could soar higher than the 42,000 pph projected? It certainly would not be unexpected. Looking at the plans for the Yonge North extension, ridership is expected to grow well past 2031. Three stations, Steeles, Langstaff, and Richmond Hill Centre are expected to increase the density around those stations by a factor of 1.85 between 2031-2051.

Looking at Steeles as a specific example, density is expected to increase from 280 people plus jobs / hectare (ppj/ha) to 519 ppj/ha. Not only will this add passengers to the subway as a result of an increase in population, but the mode share of transit increases as density increases119. What this means is that while at 280 ppj/ha, 30% of the 280 ppj/ha may use the subway, at 519 ppj/ha, 40% may use the station. Similar effects would be seen at Richmond Hill Centre and Langstaff.

Using even the most optimistic of estimates, it becomes clear that a Downtown Relief Line will need to be constructed, but why is it important to construct the Downtown Relief Line prior to the North Yonge Extension?

Even assuming that the Yonge line can cope temporarily with the addition of riders from the North Yonge extension, constructing the subways in that order is a tremendous waste of resources93. In order to improve capacity on the Yonge line, a massive overhaul of Bloor-Yonge station needs to be completed, with current estimates putting the cost at $500 million171. This is a cost that need not be borne if the Downtown Relief Line is constructed ahead of the Yonge North extension, as the DRL resolves crowding at Bloor-Yonge by providing an alternative path to downtown for travellers from the east end. Metrolinx estimates the number of riders diverted from the Yonge line to the DRL to be 17,500 pph, allowing the Yonge line to run well below capacity limits17. City Councillor Michael Thompson has estimated the cost savings of building the Downtown Relief Line rather than implementing the required improvements to address the capacity issues of Yonge to be upwards of $2.27 billion, even when including the construction costs of the relief line itself48. Though cost estimations of this project put the expense of the line above Thompson’s estimates, his point of saving the money of the Yonge improvements remains valid. Given the high cost to implement capacity improvements on the Yonge line, and the eventual need for a Downtown Relief Line regardless of those improvements, it becomes obvious that constructing the Downtown Relief Line first makes a great deal of economic sense. Yet there are many other reasons why a Downtown Relief Line is necessary.

Image Sources

From top to bottom:

Continue to Queen/King Streetcar Issues

© 2010 Phil Orr & Andrew Perry