The term physical access control refers to an exertion of power over who enters a physical space, how they enter, and when they enter. In major cities such as New York, physical access control is ubiquitous and part of daily life. For example, gaining entry to a subway station means passing through a physical access control point.
In a busy city like New York, physical access control is one of the most commonly used forms of security. Physical access control points are not simply used in public spaces. In fact, most if not all major commercial office buildings and apartment buildings in New York City have at least one form of access control implemented. For physical access control to exist, a physical barrier between the outside world and the area that is being protected must exist. The most common physical barriers at which credentials are presented are turnstiles, fences, doors locked with a mechanical apparatus such as a common lock and key, doors locked with a computer apparatus such as an electronic keypad, and a person such as a guard or bouncer.
When an individual reaches a physical access control point, he or she is asked to present a credential. A credential can be a physical object such as a Metrocard or a piece of information such as the name of an individual a person is visiting within an office building. It could also be a code such as a series of numbers as in a pin number which grants access to a physical space. Physical access control points are commonly found in major office buildings in New York City as well as in areas such as the train or ATM where it is necessary for the safety of the public to only allow certain individuals beyond a certain point. Other forms of credentials include common keys, credit cards, ID badges, and voice recognition through an intercom.
Because they involve the presentation of credentials, physical access control points are generally thought of as incredibly secure. However, there are security risks involved with access control points, due in large part to human error. It is common especially in a large building that does not have a person watching the presentation of credentials for a legitimate user of the space to hold the door for an intruder. Further, it is common for legitimate users to prop the door open, essentially forgoing the implemented system. It is therefore important that any space that utilizes an unmanned access control point system such as a key or the entering of an electronic code have set rules and regulations as to who is allowed to give access to others and whether the door is to remain closed at all times.
Access control systems come in a variety of forms ranging from simple, such as a key in a mechanical lock, to complex, such as a biometric reader which grants access based on recognition of a fingerprint. Specific access control systems are implemented in different spaces for different reasons and to solve varying degrees of security concerns.