NYC's MTA is one of the only systems where you don't (usually) have to change platforms for the express train, too. For instance, if you're going uptown on the

NYC's MTA is one of the only systems where you don't (usually) have to change platforms for the express train, too. For instance, if you're going uptown on the 6 (local), and are planning on going to Grand Central, if there's a 4/5 (express) across the platform, they'll usually hold the 4/5 for enough time to transfer. Most other systems you would have to completely change which platform. And then there's the rush hour based skip-stop service on the J/Z. The elevated J/M/Z line in Brooklyn has three tracks part of the route. In the morning, an express train uses it to go into Manhattan. In the evening, an express train uses it to go to Brooklyn. Great flexibility for a line that's used almost primarily for getting from the outer borough in to Manhattan. As for the rats .... if only they'd enclose the platforms (so edible debris didn't end up swamping the tracks), it'd go a long, long way. And also cut down on passengers being struck by trains after falling/being pushed on to the tracks.