Turnstiles
A turnstile is a form of gate which allows one person to pass at a time. It can be made so as to enforce one-way movement of people, and in addition, it can restrict passage to people who insert a coin, a ticket, a pass, or similar.
Turnstiles use a mechanism that allows linear or rotary motion in only one direction allowing entry, while preventing motion in the opposite direction.
The turnstiles are usually designed to operate:
- After a payment has been made (usually by inserting a coin or token in a slot)
- By badging a smart card or a proximity card at a proximity reader
- By inserting a ticket or electronically encoded card.
Turnstiles are often used for counting the numbers of people passing through a gate, even where payment is not involved
Thus a turnstile can be used:
- To ensure paid access, (for example public transport)
- As a ticket barrier
- To restrict access to authorized people, for example in the entrance to a factory or large site