Terminology
Parking controls are applied to on and off street parking (multistorey, ground level and underground), although the style of control will vary with the type of parking space. The ability to apply controls will also depend on local legislation. Types of parking space fall into the following categories:

• Public spaces
  
  • On-street
    
  • Off-street, operated by local authorities or private companies
    
• Private spaces (off street)
  
  • Residential
    
  • Non-residential

Parking controls can take a number of forms, including duration, cost, time of day, supply, location of spaces, permits and parking bans. Parking charges will be considered separately from the other controls considered here. The application of controls to existing private spaces can be very difficult for local authorities, as they generally do not have any jurisdiction over parking that is not for public use. PNR parking is most easily controlled through the planning process and is considered in more detail under Parking Standards for New Developments. Additionally, legislation may be required to apply other controls, such as restricting on street areas to residents only parking.

The main focus here will be car parking and the traffic impacts that controls result in. Nevertheless, parking controls also relate to, coaches, lorries, motorcycles and bicycles. Bicycle parking is often near to destinations (sometimes within pedestrianised areas) and away from heavily trafficked areas to promote near door-to-door travel and safety. Bicycle parking is generally free and relatively uncontrolled to promote use of this mode. Although, bicycle parking may be banned in some locations due to safety considerations (e.g. chaining bicycles to railings beside narrow footpaths). Similarly, motorcycle parking is also relatively near to destinations, but avoiding pedestrian areas, either on street or incorporated into car parks. Control of motorcycle parking varies between locations. Some authorities make no special provision and subject motorcycles to the same controls as cars. Other authorities – often those seeking to encourage their use instead of car travel – are more liberal. In these authority areas, motorcycle parking may be subject to no more control than bicycles, or they may have dedicated on-street spaces and reduced or no charges.

Lorry parking is also subject to control. Such parking is needed when drivers on long haul journeys park over night or during rest breaks. Consequently, access to city centres is not generally a requirement, but access to the trunk road and motorway network is. Thus, lorry parks are generally on the outskirts of cities or even in more rural areas (often near to industrial estates to minimise visual intrusion) to keep large vehicles out of town centres. Similarly, with coach parking there is a need to keep large vehicles out of town. However, there is also a need for access to town centres for passengers. Thus, coach parking is often integrated with larger car parks just outside of city centres or at key destinations such as theatres. Where coach parking is integrated with car parking, coaches will be subject to the same controls.

Long stay parking is usually off street and further from destinations, with lower charges the further away from town centres the car parks are. This is designed to keep traffic out of town centres. Another source of conflict is between commuters and residents. Residents want to be able to park outside their house, but commuters often take spaces to avoid parking charges where their work place does not provide parking for all staff. Where space is available in residential streets it also allows commuters to continue driving despite other measures to discourage car use. Thus, residents' only parking is often introduced to tackle these issues.

It is clear that parking policies establishing which type of parking and control is used where and when, must be designed not only to tackle traffic management issues, but also conflicting user needs.

Technology
Most forms of parking control now require some level of technological input. Enforcement is usually through the issuing of fines, often via a handheld terminal. These terminals operate on a similar basis to personal digital assistants (PDAs), although they also include portable printers. As with PDAs, the handheld terminals link to office based PCs to download stored data. Specialised parking management systems are available to centrally operate parking management. These systems control the recovery of fines issued, tow away schemes, the issuing of permits, number and location of spaces (sometimes real time), and any other aspect of parking management the client specifies for custom built systems. Thus, even uncharged on-street spaces subject only to a duration control require some technology. Where charges are used as a means of control, payment collection technology (on-street meters, in-car meters and smart cards, off-street pay-on-foot kiosks and entry/exit ticket and payment machines) is required. Details of this can be found under Parking Charges.

Technology also has a role in controlling entry and exit to car parks, which can be combined with payment. Off-street parking is often subject to these controls to issue tickets and regulate the volume of search traffic within the car park. Sensors built into ticket machines identify vehicles approaching a barrier or raised bollard, which triggers the issuing of a ticket. When the driver takes the ticket, this raises the barrier or depresses the bollard. The ticket machine then regulates the number of vehicles entering the car park to prevent more cars entering than there are spaces available. On exit from the car park, payment is collected through the same process or a staffed kiosk. The machines are linked to a central computer, which calculates the number of spaces available and stores data on charges received.

Increasingly, entry and exit controls merely regulate the number of vehicles within a car park; payment is by a pay-on-foot machine – drivers obtain a ticket from a machine located near pedestrian exits as they leave, and pay at the same machine on return. Tickets are then returned to the driver who inserts them into an exit control machine to prove that payment has been made.

Increasingly, real time technology also has a role in providing parking information. It is now common for direction signs to indicate when a car park is full, and in some cases, which alternative car parks have the most spaces available. Full details are given under Parking Information.