Tri pode turnstile

A turnstile, also called a baffle gate or turnstyle, 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.

Turnstiles are used at a wide variety of settings, including stadiums, amusement parks, mass transit stations, office lobbies, airports, ski resorts, factories, power plants 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.

Persons with disabilities may have difficulties using turnstiles. In these cases, generally a wide aisle gate or a manual gate may be provided. At some locations where luggage is expected, a line of turnstiles may be entirely formed of wide aisle gates.

Turnstiles often use ratchet mechanisms to allow the rotation of the stile in one direction allowing ingress but preventing rotation in the other direction. They are often designed to operate only after a payment has been made, usually by inserting a coin or token in a slot; or by swiping, tapping, or inserting a paper ticket or electronically-encoded card.