Vancouver

I disagree with the author's opinion here. Yes, there are some very busy lines that need replacing and some mid-town/up-town areas that might be underserved, especially around the universities. But building a subway/el-train to suburbia isn't a bad thing!

Yes it might be motivated by suburban political capital, but there will be a lot more new riders. Even the subway that replaces the 99-B line will have 100 000 riders but only a portion would be "new" riders who wouldn't have taken the B-Line.

I'll tell you as someone from Toronto, what happens if you play games like my city did not extending the subway north of the city limit for decades until the York University extension. By then the costs for development are way up and the disruption for any construction is enormous. Expand the transit out now, while you can.