N.Y. Railroad Law § 240: Gates or vestibule doors

§ 240. Gates or vestibule doors. Every car used for passengers upon

elevated railroads shall have gates at the outer edge of its platforms

so constructed that they shall, when opened, be caught and held open by

such catch or spring as will prevent their swinging and obstructing

passengers in their egress from or ingress to such cars, or vestibule

doors so constructed as to slide into the body of the car; and every

such gate or door shall be kept closed while the car is in motion; and

when the car has stopped and a gate or door has been opened, the car

shall not start until such gate or door is again firmly closed.