The Oil Drum: Local

Right now, the M15 limited runs every 5 minutes at peak, and the local also runs about every 4 minutes. The problem at such headways is reliability, since any delay will cause result in more people, and thus more delay, at subsequent stops, until you get 5 buses running in a pack. BRT will help mostly by making running time more predictable, if the separated lanes are done properly. And off-board fare collection, if they ever implement it, will allow for much faster boarding, also improving running time significantly. But how much can you increase capacity on a bus line? 25% maybe. And that's still nothing compared to the capacity of a subway line. But even the Second Avenue line will have rather limited capacity, since it will only have a local train, and even that will initially have to share the Broadway express tracks. So the subway capacity can only be improved by about 25% as well. And that's assuming they build the thing at all, which they haven't started doing yet, and it's far from certain that they ever will. After all, they've been promising that subway for at least 50 years.