What are Turnstiles?
A turnstile is a mechanism that allows a location to have control over entry and exit. Most turnstiles consist of a horizontal arm that extends from a post and allows persons to pass through, given the particular condition has been met. To pass through a turnstile, it might be necessary to present an authorized identification or to make payment. Other similar structures keep a count of individuals that pass through. Turnstiles provide security, control crowds, prevent loss control, and control admission and/or access. Places that commonly use turnstiles include amusement parks, public transportation, airports, and sporting events. The design of a turnstile allows only one person to pass through at a time. The initial function of a turnstile was for farmers, but not animals, to be allowed to pass through. Another use of a turnstile is to maintain pedestrian traffic in a single direction. Most modern turnstiles are mechanical, which allows the arm to be rotated one direction but not the
