In an uncharacteristically co-operative move, Metrolinx has responded to local complaints about the planned route of the Richmond Hill subway extension under the Royal Orchard neighbourhood.

Originally, the Yonge North line would have run north under Yonge Street including Richmond Hill Station and a storage yard for trains to the north. The revised alignment takes the subway east to the GO corridor before it passes under Highway 407, and the subway runs on the surface north from there with two stations.

The TTC plans a new surface yard north of Richmond Hill, although it is not clear who will pay for this and whether it is still part of the YNSE budget. It is listed as part of TTC Capital and Real Estate plans, and this suggests that part of the extension’s cost (the need for more train storage) remains in the TTC’s lap even though Ontario is funding the subway itself.

The new alignment was announced on the Metrolinx blog on December 8, 2021. I wrote to Metrolinx that day asking for details of the planned vertical and horizontal alignments, and they replied on December 9:

We are preparing to release an update to the environmental assessment for the project in the new year, which will contain more detailed analysis on this specific route. This route will also be the basis for the analysis we complete for the Preliminary Design Business Case, which is also tracking for release later in 2022. 

Email from Fannie Sunshine, Metrolinx Advisor, Media & Issues Communications

The information surfaced (so to speak) not long afterward, certainly before an updated EA or Preliminary Design Business Case. Metrolinx obviously thought better of their initial withholding of the route’s details.

On December 15, Metrolinx CEO Phil Verster wrote a letter to the Royal Orchard community going into this change at some length, and even more was provided in an online consultation session on December 16 including its presentation deck.

Horizontal and Vertical Alignments

Here is an overview of the two routes.

The horizontal alignment has been changed by placing the east-west segment directly under Bay Thorn Drive to minimize the amount of tunnel that is directly under house. This requires that the curves at either end be tightened to make sharper turns from Yonge to Bay Thorn, and then from Bay Thorn into the GO corridor. The Bridge Station planned adjacent to the existing GO Langstaff Station is not affected.

Below are the original horizontal and vertical alignment in more detail. North is to the right.

The subway would initially swing west of Yonge Street and cross under the Don River. It would then travel northeast under the residential neighbourhood with a portal in what is now an industrial area south of Langstaff Road to a surface station under the highway.

The proposed alternative has both sharper curves and a deeper path. The tunnel under the Don River is almost twice as deep (31m vs 16m), and there is a long climb to just east of Royal Orchard Park where the vertical alignments meet up. The new alignment will require slower operation than originally planned because of the tighter curve radii.

If a Royal Orchard Station were ever added to the plan it would be considerably deeper in the new alignment than the old at a depth comparable to some of the proposed downtown stations on the Ontario Line.

The vertical alignments are compared in the drawing below.

Two alignments proposed by Transport Action Ontario were rejected because of various issues such as the effect on planned developments, the complexity of the portal and Bridge Station, and the extra cost of these schemes. Metrolinx states that its revised proposal keeps the project within its budget.

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