Number of subway cars: 6,418 Number of weekday train trips: 8,200 Subway car mileage: The fleet traveled 358 million miles in 2016 Number of miles traveled by an average subway car between repairs:

* Statistics gathered using available data. Methodologies may vary among systems.

During off-peak hours, when the subway is less crowded, conductors can hold trains that enter the same station at the same time, and passengers can transfer across the platform. Subway personnel can do this as long as both trains are on schedule and waiting will not disrupt either train's schedule.

Across-the-platform transfers and connections Many subway stations let you cross the platform to change from one route to another. However, at times trains leave before customers can make the connection. This usually happens during rush (peak) hours when the subway is busiest and trains run more frequently. If a train doesn't proceed it can affect the schedule, backing up trains behind it and slowing service all along the line.

The 22 interconnected subway routes feature across-the-platform transfers between express and local service at many stations. There are also three permanent shuttle services: Franklin Avenue, Rockaway Park and 42 Street.

Serves: Manhattan, Queens, Brooklyn, the Bronx, and Staten Island through MTA Staten Island Railway (SIR). Ridership: : In 2016, average weekday subway ridership was 5.7 million, the highest since 1948. Annual ridership was 1.757 billion. Routes: Numbered routes include the Lettered routes include