Road-rule enforcement camera |
A road-rule enforcement camera is a system including a camera and a
vehicle-monitoring device used to detect and identify vehicles disobeying a road rule or road rules. Common examples include the
following:
- Speed cameras for identifying vehicles travelling over the legal speed
limit.
- Red-light cameras for identifying vehicles proceeding through red
lights.
- Bus-lane cameras for identifying vehicles traveling in lanes reserved for buses.
- Toll-booth cameras for identifying vehicles proceeding through a toll booth without the
toll being paid.
- In central London, cameras help to identify drivers who evade paying the Congestion Charge.
There are systems that are combinations of the above - for example, some systems detect both red-light infringements and speed
infringements.
History
A Dutch company called Gatsometer BV, founded by the 1950s rally driver Maurice Gatsonides, invented
the red-light camera, developed the first radar for use with road traffic, and is the
world's largest supplier of speed camera systems. Because of this, in some countries (the United Kingdom for example) speed cameras are sometimes referred to as "Gatsos". They are also sometimes
referred to as "photo radar", even though many of them do not use radar.
The first systems introduced in the late 1960s used film cameras to take their pictures. From
the late 1990s, digital cameras
began to be introduced. Digital cameras can be fitted with a modem or other electronic
interface to transfer images to a central processing location automatically, and so they have advantages over film cameras in
speed of issuing fines, and operational monitoring. However, film based systems still generally provide superior image quality in
the variety of lighting conditions encountered on roads, and new film based systems are still being sold.
Technology
Vehicle-detection systems used in conjunction with road-rule enforcement cameras include the following:
- Piezo-electric strips - pressure sensitive strips embedded in
the roadway (a set distance apart if speed is to be measured - typically 1-3 meters).
- Doppler radar - a radio
signal is directed at the vehicles and the change in frequency of the returned signal indicates the presence of a moving vehicle
and the vehicle's speed.
- Loops - inductive loops embedded in the roadway detect the presence of vehicles, and with two loops a set distance apart
vehicle speed can be measured.
- Laser - the time of flight of laser pulses is used to make a series of measurements
of vehicle position, and from the series of measurements vehicle speed can be calculated.
Systems can be car or van mounted, hand held, or fixed site. In car mounted systems, cameras and radars or lasers are fixed to
a car. When deployed, the car is parked beside a road, and any speeding vehicles driving past are photographed. Red-light cameras
are generally fixed site type systems. Many speed cameras are also fixed site type. Fixed site type systems are mounted in boxes
on poles beside the road. They are also often attached to existing gantries that hold up signs over the road, and to over passes
or bridges.
Speed camera systems that measure the time taken by a vehicle to travel between two fairly distant sites (from several hundred
meters to several hundred kilometers apart) are also being developed and introduced. From the elapsed time over the known
distance, a speed infringement can be detected, or in the case of truck drivers driving
long distances, avoidance of legally prescribed driver rest periods can be detected. Such systems take a picture of every vehicle
passing the first site, and every vehicle passing the second, then find matches between the images from the two sites. Most
commonly, this matching is done by using automatic number-plate recognition systems. Such systems have been tried
and/or deployed in only a few road jurisdictions in the world.
Verification and System Testing
The pictures taken by road-rule enforcement cameras must usually be viewed by a person before any infringement notice or
ticket is issued to the driver, and judged to be satisfactory or not. This step is known as verification, and is a standard legal
requirement in nearly all jurisdictions. Verifiers typically must check some or all of the following:
- that there is no sign of interference with the vehicle detector by objects other than the alleged speeding vehicle,
- that the number plate is unambiguously readable according to a legal standard,
- that the make and model of vehicle matches that recorded by the licensing authority for the number plate,
and in some jurisdictions
- that the appearance of the driver in the images is adequate in some way - for example, does it match the picture on the
driver's license.
In most jurisdictions, verification is carried out by the police force, although in
many places it is carried out by private companies on a fixed price basis under close police supervision. Also generally, cameras
must undergo approval testing and operational testing to ensure that they function adequately. In the US, it is common for all
installation, operation, and verification procedures to be carried out by private companies that receive payment based on the
number of infringements they issue, and often under no testing regime whatsoever.
Depending on the number of things that need to be identified in the images and the quality of the camera equipment, somewhere
between 35% and 80% of infringements result in a notice being issued to the owner of the vehicle. A legal requirement for driver
identification reduces the prosecuting rate dramatically.
Issues
In September 2001, the pictures from the San Diego red light camera systems
were ruled inadmissable as court evidence (USA Today article , Judge's ruling ). The camera program was operated and paid for
according to practices common throughout the US. Such practices give a
financial incentive for companies to verify against drivers in cases of doubt, and this was found to be unacceptable, as was the
low level of involvement by the city and police. Despite the ruling, such verification and camera operation practices continued
on a widespread basis in the US.
In January 2002, a speed camera case was dismissed in Denver,
Colorado on similar grounds of pay per infringements being illegal, and lack of police involvement in issuing of tickets.
In the late 1990s in a number of jurisdictions, there was a degree of controversy surrounding the deployment of increasing
numbers of speed and red-light cameras. Police and government were accused of "Big Brother tactics" in over-monitoring of public roads, and of "revenue raising" in applying cameras in
ways to increase government revenue rather than improve road safety. In some places, for example the province of Ontario, Canada, and the state of Hawaii in the USA, camera programs were aborted or withdrawn due to public outcry. Often when
camera deployment has been accompanied by large scale advertising campaigns explaining the justification and planned effects of
such cameras, the public has accepted their use on a large scale. In other places, public responses have included spectacular
vandalism of camera systems including attacks with explosives, tractors, cutting equipment, incendiary devices, rifles, and even
attacks on camera operators, as forms of civil disobedience and protest.
External Links
example images
against enforcement cameras
for enforcement cameras
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