Here, There, Everywhere
The title refers to cameras on the road, but not the usual red-light or speed cameras that we invariably write about. This newsletter is about ALPR.
What the heck is ALPR, and why should you be aware of it? Automatic License Plate Recognition applications are proliferating and are mobile. Many electronic plate-reading systems are mounted within cruising vehicles, and are operated by law enforcement agencies or even private, for-profit companies. ALPR systems capture and process the license plate information of any and all cars, motorcycles and trucks that cross the path of the host vehicle.
High-speed digital cameras are mounted around the periphery of the ALPR-equipped vehicle so that photographic evidence of passing vehicles, even at freeway speeds, can be gathered. License plate numbers are converted by optical recognition software to text, which can then be checked against a variety of databases, depending upon the intent of the data-capturer.
The law enforcement application is pretty straightforward. Plate numbers are compared to lists of stolen vehicles or owners with expired registrations, outstanding fines, or open arrest warrants. The mobile ALPR unit is equipped with a laptop computer, so a match can be found almost instantaneously and the location of the flagged vehicle pinpointed in real time.
Private applications of ALPR include automobile repossessions by lenders. A tow truck can be called in immediately upon locating a flagged license plate, allowing the repo man to keep motoring along on his quest to capture more license plate images and delinquent borrowers.
Much like any program that gathers massive amounts of data, the culling of the innocent from the guilty is not a perfect process; too many of the former can be swept into the process. Database information may be incorrect, license plates can be switched, vehicle registrations may not have been transferred properly to new owners — any number of things can go wrong, causing an innocent party to have to endure the hassle of a towed vehicle, or much worse if a false arrest is involved.
For more information about how ALPR works, you can view the video at the bottom of this post which shows a plate-recognition program in action by Central Florida law enforcement. The constant clicking of the cameras capturing license plate data throughout the video will give you some idea of the scope of such a program.
Want to find the speed traps in your neighborhood?
Check out the NMA’s speed trap registry at www.speedtrap.org.