Turnstile

A turnstile, also called a baffle gate, is a type of gate. It only allows one person to pass at a time.  It can also be made so as to make one-way traffic of people. It can also make passage only to people who put in a coin, a ticket, a pass, or similar. A turnstile can be used for paid access (sometimes called a faregate when used for this). For example, it can be used in public transport as a ticket barrier or at a pay toilet. 

Turnstiles are used at a variety of places. This includes stadiums, amusement parks, museums, and mass transit stations.

 Other websites 

Page showing various designs of turnstiles in the history of the New York subway system.
Turnstile Models 

Category:Gates