History: The New York City Subway, United States

Many stations have mezzanines. These allow for passengers to enter from multiple entrances and proceed to the correct platform without having to cross the street before entering. They also allow for crossover between the uptown and downtown platforms.
Passengers enter a subway station through stairs towards station booths and vending machines to buy their fare, which is currently stored in a MetroCard. After swiping the card at a turnstile, customers continue to the platforms. Some subway lines in northern Manhattan and the other boroughs have elevated tracks to which passengers climb up to the platforms and station houses via stairs, escalators, or elevators.
• Globe lamps
At most of the system's entrances and exits sits a lamp post or two bearing a colored spherical lamp. Before the introduction of the MetroCard in 1994, these lights indicated the station's availability. A green lamp meant that the station was open and running 24 hours a day, a yellow lamp meant that it was open only during the day, while a red lamp meant that it was an exit-only. The yellow lamp was phased out and replaced by red lamps, which takes over the role of both a part-time entrance and exit-only.