Tell me if this is an amazing idea, or one of those amazing ideas that actually turns out to be completely impractical (like suggesting Ontario should boost up marine shipping, but forgetting that the Seaway is iced over during winter).
I keep thinking about the idea floating around about tying the DRL, Don Mills, Eglinton & Jane lines into one
'loop' line (this was created by Mark Dowling and posted @ Metronauts). Given the high density areas it would serve, the multitude of employment zones, entertainment areas, feeder buses, commuter rail it would serve and just general uberness of it, I can't help but feel that 50 or 70 years down the line, it will be woefully under capacity.
One way to alleviate this would be to design the tunnels & stations to cope with double decker metros. My line of reasoning was that the 'loop' looks like the Yamanote line, which is actually a sort of REX line, like the RER, which itself
uses double decker trains. Is this actually a practical idea, or would something like safety regs or upfront tunneling & station design costs make it impractical? I can't help but think this would make the subway infinitely cooler.