Automatic number-plate recognition

In the other arrangement, there are typically large numbers of PCs used in a server farm to handle high workloads, such as those found in the London congestion charge project.

When Dutch vehicle registration plates switched to a different style in 2002, one of the changes made was to the font, introducing small gaps in some letters (such as P and R) to make them more distinct and therefore more legible to such systems.

[8][9][10][11][12][13][14][15] During the 1990s, significant advances in technology took automatic number-plate recognition (ANPR) systems from limited expensive, hard to set up, fixed based applications to simple "point and shoot" mobile ones.

This was made possible by the creation of software that ran on cheaper PC based, non-specialist hardware that also no longer needed to be given the pre-defined angles, direction, size and speed in which the plates would be passing the camera's field of view.

Algorithms must be able to compensate for all the variables that can affect the ANPR's ability to produce an accurate read, such as time of day, weather and angles between the cameras and the license plates.

Factors which pose difficulty for license plate imaging cameras include the speed of the vehicles being recorded, varying level of ambient light, headlight glare and harsh environmental conditions.

Exceeding threshold angles of incidence between camera lens and license plate will greatly reduce the probability of obtaining usable images due to distortion.

[21] Federal, provincial, and municipal police services across Canada use automatic licence plate recognition software; they are also used on certain toll routes and by parking enforcement agencies.

[26] In 2012 a state consortium was formed among the Hungarian Ministry of Interior, the National Police Headquarters and the Central Commission of Public Administration and Electronic Services with the aim to install and operate a unified intelligent transportation system (ITS) with nationwide coverage by the end of 2015.

[27] Within the system, 160 portable traffic enforcement and data-gathering units and 365 permanent gantry installations were brought online with ANPR, speed detection, imaging and statistical capabilities.

The system is installed on the dashboard of selected patrol vehicles (PDA-based hand-held versions also exist) and is mainly used to control the license plate of parking cars.

The Home Office states the purpose of automatic number-plate recognition in the United Kingdom is to help detect, deter and disrupt criminality including tackling organised crime groups and terrorists.

[35] These records are stored for up to two years in the National ANPR Data Centre, which can be accessed, analysed and used as evidence as part of investigations by UK law enforcement agencies.

[36][37] In 2012, the UK Parliament enacted the Protection of Freedoms Act which includes several provisions related to controlling and restricting the collection, storage, retention, and use of information about individuals.

By April 2022, 1500 cities across the United States had implemented Flock cameras, despite criticism from the ACLU and other civil rights organisations[42][43] and concerns about whether the system actually reduces crime.

[45] Mobile ANPR is becoming a significant component of municipal predictive policing strategies and intelligence gathering,[46] as well as for recovery of stolen vehicles, identification of wanted felons, and revenue collection from individuals who are delinquent on city or state taxes or fines, or monitoring for Amber Alerts.

Images, dates, times and GPS coordinates can be stockpiled and can help place a suspect at a scene, aid in witness identification, pattern recognition or the tracking of individuals.

In the show, tow truck drivers and booting teams use the ANPR to find delinquent vehicles with high amounts of unpaid parking fines.

[59] In April 2020, the Massachusetts Supreme Judicial Court found that the warrantless use of automated license plate readers to surveil a suspected heroin distributor's bridge crossings to Cape Cod did not violate the Fourth Amendment to the United States Constitution only because of the limited time and scope of the observations.

[60][61] ANPR is used for speed limit enforcement in Australia, Austria,[62] Belgium,[63] Dubai (UAE),[64] France, Ireland, Italy,[65] The Netherlands,[66] Spain,[67] South Africa, the UK, and Kuwait.

A first experimental system was tested on a short stretch of the A2 in 1997 and was deemed a big success by the police, reducing overspeeding to 0.66%, compared to 5 to 6% when regular speed cameras were used at the same location.

ANPR is marketed as able to be implemented through networks of IP based surveillance cameras that perform "double duty" alongside facial recognition, object tracking, and recording systems for the purpose of monitoring suspicious or anomalous behavior, improving access control, and matching against watch lists.

[78] The Center For Evidence-Based Crime Policy in George Mason University identifies the following randomized controlled trials of automatic number-plate recognition technology as very rigorous.

The electronic toll collection system comprises three different structures: When the smart tag is installed in the vehicle, the car is quickly identified and owner's bank account is automatically deducted.

One method increases the reflective properties of the lettering and makes it more likely that the system will be unable to locate the plate or produce a high enough level of contrast to be able to read it.

Older systems had been notably unreliable; in the UK this has been known to lead to charges being made incorrectly with the vehicle owner having to pay £10 in order to be issued with proof (or not) of the offense.

Diotte wrote an article critical of Edmonton police use of traffic cameras for revenue enhancement, and in retaliation was added to an ANPR database of "high-risk drivers" in an attempt to monitor his habits and create an opportunity to arrest him.

The police themselves have been known to refer to the system of ANPR as a "24/7 traffic movement database" which is a diversion from its intended purpose of identifying vehicles involved in criminal activities.

[131] In 2013 the American Civil Liberties Union (ACLU) released 26,000 pages of data about ANPR systems obtained from local, state, and federal agencies through freedom of information laws.

"The documents paint a startling picture of a technology deployed with too few rules that is becoming a tool for mass routine location tracking and surveillance" wrote the ACLU.