[Busy Bee]

^ B Division cars ARE very large and long (by global metro standards, they're really more like commuter/RER cars in this regard), but in terms of width I cant see how it would make a huge difference in tunnelling costs since were talking about maybe a 2-3 foot diameter difference and obviously with a cut and cover construction method would make little difference. Where it does come into play is the impressive length of NY subway train consists which dramatically affect minimum curvatures, and the big enchilada, station platform lengths. BART trains can exceed 700' and DC Metro about 600' for 8 car trains. Both of those systems where built in the developed in the 60s-70s when the idea of these regional subway systems using larger cars was the trend. But off the top of my head I think the only other cities outside the US that come close would be Moscow and Tokyo and possibly some Chinese metro line I'm not as familiar with. Even the London Tube tops out around 400' and most lines trains are significantly shorter. The Moscow Metro from its creation has a minimum platform length of about 500'. By comparison the NY Subway maxes at about 600' for 'A' Division 11-car trainsets (51' cars) and for 'B' Division stations accommodating 10 60' cars or 8 75'cars.