The Ultimate Guide to ANPR

New to ANPR? In this post we cover everything you need to know about the advanced security technology…

What does ANPR stand for?

ANPR stands for automatic number plate recognition. ANPR uses a camera, or cameras to read the number plate of vehicles as they drive by. Sharing the information with a centralised data system that holds details about the vehicle’s driver and owner.

ANPR system started life in 1976, developed by the British police to track vehicles on the M25 and help traffic police enforce the law. First used at the Dartford Crossing, ANPR was the forerunner for the UK’s ever-growing smart motorway network.

Now ANPR technology is used by law enforcement agencies worldwide and by local authorities, the Department for Transport and by private companies, mainly for car park management and traffic flow, across the globe.

ANPR has done its bit catching dangerous criminals in police investigations since the early 2000s. It is also a vital part of the anti-terrorist Ring of Steel in London.

How does ANPR work?

Surprisingly adaptable, ANPR software works alongside closed-circuit television (CCTV), traffic cameras or hardware designed solely for numberplate checking. It is just as effective on static cameras as it is on mobile devices.

A camera takes a photo of a vehicle, then ANPR uses multiple images to take into account plate orientation and skew to mitigate errors and crosscheck for accuracy. To read the licence plate information, the ANPR adjusts brightness and contrast of the image so the optical character recognition (OCR) or pattern recognition can easily pull the letters and numbers, which it converts to text data and sends to a central database.

ANPR can capture the information it needs in 1/1000th second.

Some ANPR systems complete the process in situ, holding on to the information until it’s needed, while others transmit the image and camera location for an offsite reading.

How has ANPR changed?

It’s all considerably different to the first analogue ANPR imaging technology of the 70s. Just having LED infrared lighting, as all cameras do now, improves ANPR considerably because they can catch images day or night.

It was progress like this in the 1990s that gave ANPR the boost it needed to be universally adopted. Moving from those hefty early fixed cameras, point and shoot cameras with integrated technology created an accessible, simple to use piece of hardware. As anyone who has lived through the last 30 years knows, cameras and their components got smaller, processor speeds went off the charts, comparatively, and real-time everything became a real thing. Everywhere.

What does ANPR check?

In the UK public sector, ANPR software checks number plate and vehicle information against the Police National Computer (PNC) and DVLA databases to detect vehicles being used in crime. If the information matches a car listed as wanted in a criminal investigation, the database alerts the police. Increasingly, software also captures an image of the vehicle driver to support accuracy in criminal cases.

In the private sector, ANPR checks for the same information and has the same function, but without the criminals or access to police data. For the most part, ANPR technology is used for traffic monitoring and analysis – think journey times, average speeds, returning visit counts and working out peak times.

Having ANPR in car parks eases transition to a paperless payment process and makes it much easier to run smooth parking management. ANPR also facilitates fully contactless parking, essential for COVID-19 safety measures.

Car park ANPR records time-stamped photographs at the entrance and exit. On secure sites, ANPR controls access, allowing entry only to vehicles on an approved list.

What are ANPR cameras used for?

Law enforcement uses ANPR cameras for everything from ticketing minor traffic offences to tracking murderers, rapists and terrorists. Beyond that, there are tens of thousands of ANPR cameras across the country, monitoring roads, car parks, private premises and petrol stations. They help regulate traffic flow on motorways and in busy urban areas, they help car drivers find a space in packed car parks, they keep private property secure.

More than 11,000 ANPR LEA cameras in the UK add 50 million records to the ANPR systems each day (source)

1. As a police deterrent

In the UK, ANPR’s main public function is to “deter, detect and disrupt” crime and terrorism by storing millions of records each day on the National ANPR Data Centre. Even if a vehicle hasn’t been involved in an incident, its image and information is held for up to two years, just in case.

The first time ANPR helped in a criminal investigation was in November 2005 when it was instrumental in convicting the murderers of PC Sharon Beshenivsky. Now police ANPR intercept teams use statistics to be in the right place at the right time to prevent crime or stop it while it’s in progress.

2. As ANPR-integrated CCTV

Where people gather, vehicles exist. Many out-of-town shopping centres have free car parking to draw customers to their shops and encourage them to spend. It is not unheard of, though, for people to abuse those free car parks, leaving their car for hours – say if the shopping centre is near a sports stadium that charges for parking – or for days if they use the shopping mall’s parking while they head off on holiday from a nearby airport. After all, public transport between malls and transport hubs are usually frequent.

To counter this problem, car parks can use CCTV to monitor the time a vehicle arrives and leaves, using a cloud-based ticketing system that sends information 24/7. The system will alert security when a vehicle overstays its welcome. We have done this at numerous locations UK-wide, including installing an ANPR/CCTV system at Coventry’s Arena Shopping Centre, where many football and rugby fans used to park – although not so many park there these days as a result.

3. As petrol station sentinels

Petrol station drive offs have considerably reduced since the arrival of ANPR on forecourts across the country. The details of a drive off can be instantly shared with the police and with other local petrol stations. But ANPR on forecourts can go so much further. Information from the camera is forwarded to the point of sale, so staff can greet a loyalty card customer by name. Integrated software can even enable targeted advertising on the pump while the customer stands passively filling the car.

4. As car park management and security

ANPR delivers next-level car park management that goes so far beyond getting paid. As it operates 24/7, staff no longer face confrontation, and the property is protected day and night. Tickets for overrun parking go out by post, again, creating a more streamlined system. Beyond reduction in staffing costs, ANPR provides real-time statistics, using customer insights, behaviours and habits to guide business decisions.

ANPR information can inform when it might be prudent to have staff on site; its clarification of arrival and duration patterns can help with planning pricing, capacity and revenue generation possibilities.

5. As a trial or temporary solution

ANPR works as a constant solution but there are also deployable systems that use a moveable camera tower. They easily integrate with existing systems and offer an effective off-grid solution to site security or parking ticketing. They work effectively for schools, hospitals, construction sites and one-off events. They’re also a really useful way to try ANPR before investing in a complete infrastructure.

Number-plate recognition goes so far beyond catching criminals. It can be an integral part of a business strategy for private enterprise. Find out more about our ANPR solutions.

Get in touch with Guard Tech Security for a chat about how to elevate your income while reducing costs.

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