AI-backed stop sign cameras help slow down drivers
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States and localities are experimenting with the technology to catch scofflaws, but are still verifying suspected violations using human officers.
Cameras mounted on stop signs with technology driven by artificial intelligence are proving to be a fast way to get drivers to slow down.
The Maryland towns of Morningside and Colmar Manor have seen an almost 50% decrease in stop sign runners since implementing cameras in January, about nine months after the Prince George's County Council passed legislation authorizing the use of stop sign cameras within the county and its municipalities. Legislators considered last week another bill that would authorize them in Montgomery County.
“We have a ridiculous problem with people and stop signs here,” said Morningside Police Chief Dan Franklin. At one intersection alone, 87% of drivers blew past them.
In nearby Colmar Manor, the average number of violations per day was about 500. “I wasn’t expecting to see numbers this high just because we have only 1,600 residents,” Town Administrator Greg Holcomb said.
Both places have implemented the LetsDriveSafer initiative, powered by Obvio, a maker of traffic cameras that use AI. Morningside has installed six camera systems, while Colmar Manor has three.
The cameras record video of vehicles and then AI analyzes it for failures to stop.
“As the video feed goes into the device, the device itself is processing every frame and determining, ‘Here’s the vehicle, here’s the speed that it’s going, and here’s whether or not it stopped at the stop sign,” said Dhruv Maheshwari, Obvio’s founder. “Based on that, it automatically determines, ‘OK, this was a violation.’”
The system then shares only video of suspected violations with the local police department for a human to review.
“There’s some degree of discretion, which is horribly important because, as sharp as AI as a whole concept is, I still, to this minute, will tell you that I don’t believe it replaces an officer,” Franklin said. “It’s a wonderful tool. It is certainly another fantastic enforcement option to have in the toolbox. But overall, at the end of the day, you still have a trained law enforcement officer making that decision.”
“Most of the violations that get through to us, they're the flagrant ones,” said Colmar Manor Police Chief Tracy Stone. “Number-wise, I think we’re rejecting about 10%.”
When violations are verified, Obvio’s technology connects with the appropriate Department of Motor Vehicles to confirm the address connected with the license plate on the offending car and mails a citation.
What’s more, the technology can catch more violators than officers on the street can, Maheshwari added. “It allows an officer sitting in a room to give out 50, 100 violations in a specific day, as opposed to if they're out on the street, maybe they can give out five or six violations,” he said.
“Even if I put a cop at every stop sign, we're not going to get a 50% reduction in violations like I’m getting now,” Franklin added.
Colmar Manor had looked at other ways to slow drivers, such as speed bumps and stop signs with flashing lights, but Maheshwari said they needed to think differently.
“That was the crux of what we were thinking about,” he said. “What is the approach and what’s the right way to help people change their behavior, and then what is the underlying technology that can support that? … As we do different kinds of interventions, like warning letters and citations, we can now start seeing behavior change.”
Although pushback about the cameras has been minimal, Franklin said he’s not concerned with hurting feelings.
“Whether somebody stops at the stop sign because it's the right thing to do or because they’re mad and they don't want to get a ticket, I really don't care as long as they stop at the stop sign,” he said.
Similarly, the Fairfax County Public Schools system in Virginia is cracking down on the number of people passing stopped school buses that have their stop sign arms extended — a function that occurs when children are getting on or off the bus. Starting this month, 50 of FCPS’ 1,650 school buses have cameras from Verra Mobility installed on the stop sign arms to catch offenders.
“When the bus stop arm extends, that triggers the cameras to be on…so it’s not recording all traffic,” said FCPS Chief Operating Officer Andy Mueck. They point to the front and back of the bus so that “whether you’re going against the bus or passing around the bus, it’s going to trigger [the cameras’ sensors] to get a video and still picture with a license plate.”
The video is stored in the cloud and transmitted to Verra Mobility, where humans review the imagery. When violations are confirmed, the company works with the Fairfax County Police Department and court system to issue citations.
A warning period starts April 9, and citations will start going out May 12.
“It’s a self-funding initiative, cost-neutral, so the money that comes in from the $250 citation, when they start issuing the citations, completely funds the program,” Mueck said.
FCPS has the second largest bus fleet in the country, behind Greyhound, so outfitting all of them isn’t feasible, he added. But as behavior changes in one area, the buses with cameras can be relocated to other hot spots.
Children are at greatest risk for a school bus-related injury when they are boarding or leaving the bus, according to the National Highway Traffic Safety Administration. “A safety program like this that does not cost anything to run is just awesome,” Mueck said.