It seems to me, from what I've read and encountered, that Toronto has managed to retain a significantly greater railway infrastructure than a lot of other major North American cities. It would've been easy for the downtown railway lands to be disassembled and plowed under for an expressway back when that kind of "progress" was in vogue - that they weren't is to our benefit, mostly.
This is part of the Toronto railway system, looking northwest from Dundas Street West toward Weston. Today GO Transit's Georgetown line trains use this track; it's also where Blue22's "400 TOXIC diesel trains" will run between Union Station and Pearson Airport. The real tragedy of that scheme steadily moving from paper to reality is that it prohibits anything else, anything more deserving, from using the corridor. Look at it - it'd be perfect for an aboveground, western arm of the Downtown Relief Line.
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