A turnstile, also called a baffle gate or turnstile is a form of gate which allows one person to pass at a time. It can also be made so as to enforce one-way traffic of people, and in addition, it can restrict passage only to people who insert a coin, a ticket, a pass, or similar. Thus a turnstile can be used in the case of paid access (sometimes called afar gate or ticket barrier when used for this purpose), for example to access public transport, a pay toilet, or to restrict access to authorized people, for example in the lobby of an office building.
Turnstiles are used at a wide variety of settings, including stadiums, amusement parks, mass transit stations, office lobbies, airports, ski resorts, and casinos.
From a business/revenue standpoint, turnstiles give an accurate, verifiable count of attendance. From a security standpoint, they lead patrons to enter single-file, so security personnel have a clear view of each patron. This enables security to efficiently isolate potential trouble or to confiscate any prohibited materials. On the other hand, physical barriers become a serious safety issue when a speedy evacuation is needed, requiring emergency exits that bypass any turnstiles.