A 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 human traffic, 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, 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.
