Sunk cost fallacies aside, Billy Bishop does not offer any sort of redundancy in the event Pearson goes down. I'd love to see an argument that claims a significant amount of GTA GDP is dependent on that tiny airport. What Billy Bishop does offer is a good home base for helicopters, and we can do that with even less runway.
I didn't mean redundancy in that case, but overall capacity. Look at the mess London is going through trying to add an extra runway to LHR - and that's
with a multitude of alternative airports. It's not redundancy - it's overall capacity. Pearson only has 2-3 runways operational at a time, if YTZ disappears, we effectively drop the number of landing slots in the city by 25-33%. We are already at the point where the city essentially has no general aviation airports, Oshawa is the closest.
Yes, YYZ handles the biggest, "highest value" flights, but if YTZ disappears, all the traffic operating out of YTZ needs to be routed to YYZ and will need to compete for those 2-3 runways.
Regarding sunk costs, that's far from a fallacy. Shutting down an airport with a couple of billion of infrastructure, much of it less than 20 years old, to replace it with a park would not be a "fallacy". It would be actively detrimental to investment and limit infrastructure availability.
YTZ does not control some massive portion of GDP, no. But it feeds into it as a key part of the wider picture. Deleting it would not send the city into deep recession - but that doesn't mean it's a good idea, and it doesn't mean that looking to expand it would also not
help improve overall productivity. New transportation infrastructure is critical to supporting productivity, and this city has built remarkably little in the last 20 years. At the very least we should not be looking to destroy the few underbuilt assets we do have.
