Archive for the ‘Parking Guidance and Information (PGI) systems’ Category


Thursday, March 25th, 2010

Advanced Parking Systems obtain information about available parking spaces, process it and then present it to drivers by means of variable message signs (VMS). APS is used in two ways: to guide drivers in congested areas to the nearest parking facility with empty parking spaces and to guide drivers within parking facilities to empty spaces. Although the former function is more common, guidance systems within parking lots are becoming more common. This growing number of guidance systems addresses drivers’ need for more information about the position and number of the spaces that are actually available within a parking structure. These systems reduce time and fuel otherwise wasted while searching for empty spaces and helps the car park operate more efficiently.

The need for APS is most prominent in highly dense areas, where the search for parking facilities congests and interrupts traffic flows.


Basics of Parking Guidance Systems

Parking Guidance and Information (PGI) systems, or Car Park Guidance Systems systems are based primarily on the use of message signs to give drivers information regarding parking availability. The systems combine traffic monitoring, communication, processing and variable-message sign technologies to provide the service. PGI systems are designed to aid the in the search for vacant parking spaces by directing drivers to car parks where occupancy levels are low.

The availability of parking spaces in each facility is obtained from sensors that count the number of cars entering and exiting or, in other cases, by comparing the tickets issued at machines or cash registers to the capacity of the facility. This information is sent to a central or main computer that processes it, determining the locations of available parking. Availability is generally expressed in terms of “full” or “empty,” but in some cases the actual number of spaces is given.

A problem with showing actual numbers is that when the number is small, drivers tend not to enter because they think that all of the spaces will be taken by cars already in the facility. This would not actually happen because the availability takes into account cars that have already entered the facility. The systems include VMS that show parking availability and nearest parking facilities. In some cases static signs guide drivers to the facilities. Other means of providing availability information are via roadside radio terminals, where small static VMS show the frequency at which it is being broadcast; by phone, where automated answering machines can give information on congestion and parking availability; via the Internet, where one of the main services is to provide information and parking reservations; and via in-vehicle navigation systems.

Example software used to control PGI systems

A Parking Guidance and Information system has four essential elements:

  • Vehicle monitoring
  • Communication
  • Instation control system
  • Variable Message Signs (VMS) or Changeable Message Signs (CMS)

Monitoring equipment must be installed at parking areas to establish the flow into and out of the car parks in order to calculate the number of available spaces. Vehicles entering and exiting car parks are often monitored through activation of existing barrier equipment, infrared, radar detector or by underground inductive loop. Real-time vehicle counts within car parks are held on count-stations or out-stations made up of firmware apable of handling the count data.

Car park count data are transmitted back to a central location or in-station, and processed through PGI software on a standard PC. PGI software is often capable of producing occupancy statistic and flow rates for traffic analysis. Variable-message signs are located at suitable decision points on the network present the information, so that a driver’s journey time to a vacant space is minimised. VMS generally show the number of vacant spaces or information such as “Spaces”, “Full” and “Closed”. Car parks are often grouped into zones to reduce the information that has to be presented on a single sign.

Communication systems between out-station and in-station, and then in-station to VMS also required. Systems can be hard-wired, however, for city wide projects wireless communication including GPRS may be suitable.

Integrated systems allow the user to exchange information between applications more easily avoiding duplication and potentially reducing communication costs. The UTMC Specifications offer a means of achieving integration efficiently, while allowing the adoption of the latest technological developments.

Multi-storey car park application of a PGI system

Multi-storey car parks

As well as city-wide applications, PGI systems can also be used for internal multi-story car park applications with entrance signs and level-by level signs.

Protective parking schemes

Parking Guidance and Information Systems have been used within protective parking schemes. These schemes are designed to minimise disruption and discourage visitors driving to major events in residential areas. Under such schemes, only eligible residents, their visitors and local businesses would be able to hold Event Day Permits, allowing them to park in the roads in the Event Day Zone when major sporting or music events are held. One such scheme is now employed by Brent Council at Wembley Stadium. This means any visitors driving to events at Wembley Stadium without a pre-booked parking space, will not be able to park in the surrounding streets. A Parking Information System consisting of VMS and a control in-station is used to inform residents and visitors alike of the Event Days when parking restrictions apply.

Benefits of APS/PGS

  • Reduction in time spent searching for parking. The efficiency and accessibility benefits from reduced searching can also result in some reductions in accidents due to reduced driver frustration
  • Reduced pollution. Changes in pollutant emissions due to PGI are most closely related to changes in overall travel time, for example, annual pollutant emissions are reported to have been reduced due to a PGI system in Munich, Germany.
  • Reduction in congestion due to fewer cars driving around searching for spaces.
  • Elimination of queues entering parking facilities because drivers will not go to a facility where there is no available space.
  • Reduction in illegally parked vehicles.
  • Better distribution of flow and parking demand through the area.
  • APS systems result in higher revenues and profitability for the parking facilities.