in Automatic License Plate Recognition (ALPR) systems are changing the way
police work is done. Until ALPR technology, our only resources were manual
computer entry or a radio call to run a plate, both of which can compromise
officer safety and lower efficiency. ALPR technology eliminates the need to
enter plate information manually into our mobile data computers, so we can redirect
our full attention to driving and on-view (OV) patrol work. Instead, the ALPR
system does the work for us.
How ALPR Systems
cameras and database technologies, ALPR systems operate in the background and
automatically scan all license plates within view. The most advanced ALPR
systems can read thousands of plates per hour—there’s just no comparison to
what we can enter manually and the number an automated ALPR system can run.
system then processes the information using recognition software and runs the
plate against connected local, state and national law enforcement databases to
determine if vehicles are stolen, if registered owners are wanted, or if their
driver’s licenses are suspended. No action is required from the officer until a
match is received on a vehicle. These hits are immediately flagged both audibly
Not all ALPR
Systems are Created Equal
ALPR systems combine hardware and software packages including specially
engineered dual-system cameras with full-color and infrared imaging
capabilities. These systems rely on this combination in order to obtain clear
images of license plates. However, they can only read license plates at a fixed
distance of 10 to 15 feet. To function properly, the cameras require mounting
on the exterior of the patrol car and at a fixed angle of 45 degrees to the front
of the car, restricting the viewing field.
more advanced ALPR systems are software-only and eliminate the need for special
hardware. They work with a wide range of off-the-shelf surveillance cameras and
use traditional optical plate recognition along with object recognition, which
gives them the ability to distinguish and read license plates from virtually
any video source.
have used both traditional ALPR systems and, most recently, I have been testing
a software-only ALPR system from PlateSmart. I’ve been using the software in my
patrol car for more than a year and have seen the results of this advanced ALPR
image recognition is the most important part of any ALPR system. I couldn’t
make adjustments with the old ALPR system. They were permanently mounted in a
secure box on the outside of my patrol car. However, with the software-only ALPR
system, there is no need to install bulky, conspicuous cameras on the outside
of my car.
cameras are mounted in the windshield with one pointed right and one left,
which allows me to sit on the shoulder from a safe distance and automatically
run plates, and even capture traffic in the far lane. I’m able to easily
fine-tune my cameras for the situation. I can aim and focus my cameras to
reduce blind spots and I can zoom in to read plates at any distance.
can even monitor from the highway access road on U.S. Highway 19, which cuts
through the City of Clearwater. Vehicles on this stretch of highway travel at
high speeds, but I can sit behind a concrete barrier where it’s safer.
Come Rain or
in-car video cameras also enables these advanced ALPR systems to function on
bright sunny days and during heavy rain and other harsh weather without
affecting the ability to accurately read license plates. When the sun is rising
and I’m watching westbound traffic, I can make a simple tweak based on the
angle of the sun and get rid of glare so the plates aren’t blown out.
can make these adjustments on the fly and as frequently as needed. I’ve even
tested my current ALPR system during a tropical storm and it still performed at
88 percent accuracy. The cameras are covert and protected from the elements,
and the settings are simple to adjust. You don’t have to hunt for them in a
program—it’s all right there in your face.
Hits as They Come
any given day, 75 percent of the hits from the ALPR system are suspended
driver’s licenses. Others are primarily non-criminal violations. I have
adjusted the settings to provide customized sounds based on the priority of the
hit, so I can immediately recognize a stolen vehicle or missing person as
opposed to expired tags. When I hear the higher alert, the adrenaline starts
pumping and it’s go time.
one such incident, I was on a grass shoulder monitoring traffic when I heard
the high priority alert. The ALPR system let me know that the hit was related
to a missing person. I checked FCIC/NCIC to verify the validity of the alert
and found that vehicle was associated with a missing endangered persons report
from the department south of Clearwater.
immediately requested backup and conducted a high-risk traffic stop on the
vehicle. The driver was verified as being the missing person and was taken into
protective custody. Without the ALPR technology that day, I would not have
known this car drove by and this individual would not have been found so
quickly. The outcome could have been very different.
of the greatest risks officers face on a daily basis is approaching an unknown
vehicle during a traffic stop. We have no idea what to expect from the
vehicle’s driver or its occupants. However, advanced ALPR technology gives me
real-time, actionable intelligence that results in improved safety. I don’t
have to be right up on the car in a bad situation. I can zoom from various
distances and quickly get the information I need. The systems works for each
person the way you want it to, rather than preset and fixed. That’s something
that can’t be done with other systems.
greatest barrier to large, department-wide deployments of ALPR systems has
always been budget. These systems don’t come cheap. Traditional hardware and
software packages run about $25,000 per car, while the more advanced systems
typically cost significantly less ranging from $10,000 to $15,000 per car.
department has budget constraints, but the price tag for the software-only
system is much easier to swallow. It’s a substantial costs saving and the
flexibility, customization and user-friendliness can’t be beat.
or night, rain or shine, these systems just work. It’s like having multiple
sets of eyes in my car. My traffic activity is a lot higher and, at the same
time, I can concentrate on my surroundings, which means I can proactively
police my community and better serve our citizens. These advanced ALPR systems are
a force multiplier that can help officers stay safe, fight crime, and save
lives, and they will have a lasting impact on the way police work is done today
and in the future.
Klein is with the Clearwater, Fla. Police Department. He has been a Patrol Officer since 2004 and a Traffic Homicide Investigator since 2008. He can be reached at firstname.lastname@example.org.