June 27, 2005 By Merrill Douglas
Parking enforcement can be a labor-intensive job.
Officers read meters, chalk tires and return to see if the cars moved, scrutinize permit stickers, and drive around looking for vehicles whose owners haven't paid their parking fines.
Sacramento, Calif., is one of the latest cities to streamline these parking enforcement activities with help from license plate recognition (LPR) software, mobile computing and GPS technologies.
Since July 2004, the city has piloted AutoFind, a mobile LPR system from Montreal-based AutoVu Technologies.
In 2004, the city Department of Transportation's (DOT) Parking Services Division installed an AutoFind unit on one of the three-wheeled scooters officers drive when checking for illegally parked cars. It also installed one on its boot truck, which is used to hunt down vehicles with five or more unpaid parking tickets and install boots on their wheels. The city equipped a second scooter this spring and may eventually add more to its 30-scooter fleet.
"We're going to keep adding to the extent that it makes sense to do so," said Howard Chan, the DOT's parking services manager.
AutoFind's onboard equipment includes four digital cameras, a GPS receiver and a mobile computer with touchscreen interface. As the enforcement vehicle drives by, two cameras, mounted on the vehicle's roof and pointed to the right and left, capture images of license plates on parked cars. The system stores these images and uses optical character recognition to translate the numbers into machine-readable characters.
The system also notes when and where it acquires each image. Two other cameras, mounted on the rear of the vehicle, photograph the tires of parked cars.
No More Chalk
In Sacramento's parking enforcement application, an officer drives a scooter through a designated area -- perhaps 10 or 12 blocks in a two-hour parking zone -- capturing vehicle images and data. "We've automated the process of chalking tires," Chan said. Two hours later, the officer drives the same route. The system compares the license plate numbers and geographical positions to the list acquired on the previous drive.
"If there's a match with someone who's stayed there more than two hours, there's an audible beep," Chan said. "Then we're notified that the vehicle's in violation." The enforcement officer loads a picture of the plate onscreen and does a visual check to verify that it's the same vehicle. "If it is, we issue the citation," Chan said.
Along with the license plate image, the screen can display the vehicle's position on a digital map, so the officer can compare its locations at time one and time two, said Tom Keeley, AutoVu's vice president of sales and marketing. The officer can also view pictures of the tires, and if the valve stems are in the same position in both pictures, that's further proof the car hasn't moved.
The DOT installed AutoFind on its boot truck to help find more parking scofflaws. In the past, two officers patrolled the city, carrying a printout with the license plate numbers of hundreds, even thousands, of drivers with five or more unpaid parking fines. To compare vehicles on the street with vehicles on the list, they had nothing but their eyes.
Now the DOT downloads a current database of repeat offenders into the AutoFind unit each morning. When the system locates a plate number that's on the list, it alerts the officer, who verifies the car's identity, and if appropriate, installs a boot.
The technology made a dramatic difference in the boot program, Chan said, noting that in fiscal 2004, before the city implemented AutoFind, the DOT booted 227 vehicles, while in the first nine months of fiscal 2005, through March, the city booted 612 vehicles.
"If we project that out to the end of the year, we're going to do over 800 by the