Measure type: Access control
Access control is the measure of reduction of risk by regulating and controlling the flows of traffic into and out of an area or object.
Contents
Description
The aim of access control is to be able to determine who can or can't enter a particular area. This discrimination can be done on various characteristics such as whether one is in possession of a ticket, has registered in advance, the time of day, the place of entry, the mode of transport, etcetera.
This approach involves architectural features, mechanical and electronic devices, and related means for maintaining prerogatives over the ability to gain entry. Both dynamic measures (moving, acting such as boom barriers or guards) and static measures (passive, such as bus traps or heightened curbs) can function as access control mechanisms.
Another application of access control are environmental zones or low-emission zones (LEZ) with the aim of improving the air quality. Only low-emitting or zero emission vehicles are allowed to a LEZ [[1]].
Various means of access control are feasible, such as:
- Key control systems
- Electromagnetic doors, openable only by qualified personnel
- Door guards
- Barriers, both static and dynamic
- Partitioning off of selected areas during "downtime" hours
- Reduced number of building entrances
Essential conditions
For access control to work, one has to make sure that alternative entry routes are made impossible. For example, erecting a control post at a stadium is useless if the entrance next to it is unguarded. This means that for this measure to work, the access control has to be active at all designated entry points and all other access to the area have to be sufficiently blocked.
In practice this means that this measure usually needs to be accompanied by other measure types, such as target hardening and/or directing traffic flows to prevent uncontrolled entry points.
Requirements to the urban environment
For access control to be effective, the object or area should support a careful consideration of access and exit points, conforming to the use of the object or area. This holds both for the number of accesses and exits and the measures used to enforce it. A football stadium, for instance, can enforce rather imposing access control measures, in some cases extending to screening and the use of violence to enforce it and still requires quick access and exit of multitudes of people. At a service-oriented facility, this type of access control would be out of place and inappropriate and less imposing and more user-friendly measures of access control are required.
To prevent ethical issues, one should make sure to be transparent about the discrimination criteria and make sure these conform to anti-discrimination legislation and customs.
At closed entrances (if only to a particular mode of transport) information should be made available when and where a person/vehicle might gain access.
Effectiveness
Economic effectiveness
Access control does not only reduce the risk of security threats, but also requires time and money by private agents, companies/developers and the public authorities, exacting economic costs. Together, the benefits and costs are referred to as economic impact of security measures. The costs of access control measures contain the relatively straightforward direct expenditures on capital equipment and operational costs (both temporary and permanent), and in addition generate various types of secondary effects. Access measures like closed roller shutters or big chain locks in shopping streets are classical examples of measures that do not create a welcome environment, creating secondary/indirect economic effects as a result of a reduction of the perceived security and quality of the environment. On top of that, access control measures can cause negative indirect effects for commercial venues like convenience stores. These negative effects are caused by a decrease in accessibility, reducing the amount of customers and increasing the costs of distribution.
Whether the costs are making sense from an economic point of view, depends on many factors, and can be answered by two distinct sets of questions:
- Are the envisioned access control measures cost effective from a socio-economic point of view, or are there better alternatives?
- Which specific agents (individuals, companies, sectors, authorities) are affected by the access control measures, and to which extend? How do the envisioned measures adjust the behaviour of these agents, and of course the behaviour of criminals/terrorists?
Economic tools can help the decision makers to answer these questions and to prevent wasteful expenditures on security (of course in collaboration with insights from criminology, sociology, etc.).
Side effects
- Designing out: ethical issues
- Perception of unfriendlyness
- Highly visible measures like guards raise prominence of building, which can attract fanatics
<undesired impact on urban planning principles>
Footnotes and references
