How ANPR works
- A camera, usually with infrared illumination, captures an image of the vehicle in daylight and at night.
- Software locates the plate, reads the characters and recognises the country or format, with a confidence score per read.
- The result is matched against a list or database — permits, a low-emission zone register, a parking session — or combined with a second camera, for example to calculate an average speed or a travel time.
Where ANPR is used
- Ticketless parking and access control for car parks, campuses and logistics sites.
- Enforcement of low-emission and zero-emission zones (LEZ/ZEZ).
- Access control for pedestrian zones, school streets and delivery time windows.
- Section control, where the average speed between two cameras is calculated.
- Travel-time measurement and origin-destination studies, using anonymised matching.
- Identification of vehicles at weigh-in-motion and enforcement sites.
What determines recognition quality
- Camera position, angle and distance to the plate.
- Illumination, shutter speed and resolution matched to vehicle speeds.
- Plate formats and characters of the countries to be recognised.
- Dirty, damaged or obscured plates, and weather conditions.
Good site design and regular checks of the read rates matter as much as the camera itself.
Privacy and data protection
Number plates are personal data under the GDPR. An ANPR system therefore needs a clear legal basis and purpose, data minimisation, short retention periods, access control and, often, a data protection impact assessment. For travel-time measurement, plates can be pseudonymised so that only matches are kept. These rules shape the design of the system.
Integration with other systems
- Parking and access: opening barriers, starting and ending parking sessions and handling permits and whitelists.
- Zone enforcement: matching reads against vehicle registers and exemption lists, and passing possible offences to a processing back-office.
- Traffic management: anonymised travel times and origin-destination data for operators and models.
- Combined sites: WIM, section control and access control can share cameras, power and communication where the purposes are compatible.
How Urbiflow helps
We design ANPR sites and select cameras, integrate them with parking, access and enforcement back-offices and with vehicle registration databases where this is legally provided for, and build in privacy requirements from the start.
Relevant for: Cities & municipalitiesParking & mobility operatorsRoad & highway authorities