From another thread:
I don't mind at all if DRL opens 2 or 3 years after YN. There would be a number of ways to manage the capacity for such a period.
The problem is that they won't have funding for 3 subways. Even if they set aside $5 billion and get the same federal amount, they will have to spend ~ 4 billion on SSE and the remaining 6 billion will fund either DRL or YN but not both. If YN wins, the DRL will have to wait at least 4 years, possibly more.
Like what ways, exactly? They can't even manage the capacity now without it turning into a gongshow. Don't tell me ATC is going to resolve the issue, because the stations can't even handle the loads now.
AoD
In the particular scenario I was responding to: DRL is firmly in construction when YN opens, and opens within 3 years after YN; I would take the following steps in the interim:
A) Limit the number of trains going to Richmond Hill in the weekday morning rush. Only 1 in 3, or 1 in 4, trains would go there, the rest would turn back at Steeles or at Eglinton.
B) Introduce a surcharge ($1 or $1.5) for boarding at any of the 3 Yonge stations north of Steeles (weekday morning rush only, say 7 to 9 am).
C) If technically possible, add 2 southbound morning GO trains from RH to Union, and 2 or 3 northbound evening trains; and set a discounted fare between RH and Union.
Once DRL opens, all those temporary steps will be undone. There will be more trains to RH, flat TTC fare at all subway stations, and regular GO fare.
That's not ideal and will make some people grumpy, but at the end everyone will get what they need most. York Region will get its coveted subway, and full planned service / flat fare 3 years later. Torontonians will feel a bit squeezed for 3 years, but will get DRL at the end.
Now if we end up with YN in service, but DRL still in the wishful thinking phase, that's a different kettle of fish. Honestly I wouldn't know how to manage that situation.