December 29, 2023

Licence Plate Recognition (LPR/ANPR) and how to overcome plate misreads

ANPR/LPR is the creme de la creme of parking access systems, but it doesn't come without its challenges. We explore how to overcome plate misreads from LPR/ANPR.

Licence Plate Recognition (LPR/ANPR) and how to overcome plate misreads

Parkers have a universal opinion that license plate recognition (LPR), also known as automatic number plate recognition (ANPR), is the crème de la crème of parking access solutions – and we agree.  No wait times, no interaction and no paystation queues. It is, however, not without its challenges from an operational perspective. So what can be done to resolve these issues and make it even better?

For those who have no experience with the digital reading of license plates, there are a number of issues that can prevent an accurate read:

·   Malformed and damaged plates

·   Obscured plates – bicycle racks, over-hanging equipment etc

·   Deliberately altered plates

·   Rear plates only – some jurisdictions allow for the use of rear plates only

·   Varying plate heights – think of pickups vs low sports cars

·   Anniversary and pictorial plates

·   Temporary custodianship – loan cars, rental cars, family member’s cars

There is no vendor of ANPR that claims to have a 100% positive read rate- even if they get 99% success, that is still 1 issue in every 100. However, there are two cameras involved, one on entry and one on exit; so what happens when plates are mis-read or unreadable? There are two cameras involved, so mis-reads can occur on both entry and/or exit, giving parkers at the barrier arm a stressful experience. Getting them out of the car park usually involves interaction with somebody either remotely or locally, and usually through hard to hear intercoms.

In an increasingly digital world, traditional fallback mechanisms like ticket spitters are being removed for efficiency and cost reasons. This leaves parkers stranded and frustrated with no option and a severe case of front of queue anxiety (FoQA).

So we know the problem, but what are parking technology companies doing to fix it? Inugo has tackled this problem head on by allowing the parker to alternatively get access through an app on their mobile phone. Using its industry proven Bluetooth gate opening technology, the parker is given a second robust method to get out of the park. It does involve having to download an app, but the app is also used to manage license plates, review historical parking, manage payment methods and to book a park in advance - so there are lots of reasons why parkers would already have the app loaded.

The key ingredient in using another technique, say scanning a QR code, is that you need to be able to uniquely identify the parker so that you can correctly establish entry and exit times to charge the appropriate fee.  

Older methods that could have enabled a simple scan to open an entry gate have been eliminated by the restriction of access to phone attributes that can be tracked. Rightly, you can no-longer determine a tracking id or phone number without the user’s consent.  

Remembering that we want to be able to associate someone with their entry and exit, we would need to prompt them to enter something (e.g. their license plate) right at the very moment you are suffering from FoQA - would you be able to remember your license plate?

Having a robust fall back system for your LPR-controlled facility ensures that your parkers will always have the best customer experience possible from your parking management system - the world can always do with less anxiety. Check out the end-to-end Inugo digital access and payment solutions and how they can provide your facility with the best access and payment technology possible.