Whether you’re in a car, on a bike, or simply stepping into a crosswalk, you should always pay attention to traffic lights. The simple green-yellow-red light system, which has been standard in the United States since the 1910s, is a well-established tool of transportation safety. And yet, this straightforward technology can sometimes fall short. More than 50% of fatal or injury-causing car collisions occur at or near intersections, according to the Federal Highway Administration (FHWA).
NoTraffic, a real-time autonomous traffic management platform, suggests that traffic lights at intersections can do more to make intersections safer and more efficient. Instead of just relying on road users to pay attention to traffic lights, the traffic lights should be paying attention to how people are using the road.
Developed in Israel and now in use in several U.S. cities, NoTraffic is an alternative to the simple time-based ways that the typical traffic light tries to control traffic at intersections. NoTraffic’s platform uses artificial intelligence, cloud computing, and hardware installed in the low-tech traffic lights dangling above intersections. The high-tech, low-tech combination can turn a typical signaled intersection into an autonomously controlled traffic optimization device. It phases signals along thoroughfares to keep traffic flowing instead of idling at stoplights. It also replaces the conventional timer-based light changes that can catch drivers off guard, sending them careening through a red light or slamming on the brakes for a yellow. By coordinating light changes based on the actual flow of traffic, NoTraffic’s system can keep traffic moving smoothly and avoid the tricky light changes that lead some drivers to make unsafe decisions. And in the future, it could even provide alerts about dangerous drivers and other unsafe conditions.
Researchers and companies around the world are beginning to develop similar technology. The Germany-based Fraunhofer Institute for Optronics, System Technologies and Image Exploitation (IOSB) has been testing an AI-controlled traffic light system, and Google has piloted similar efforts in Israel.
NoTraffic CEO Tal Kreisler says this technology represents a significant change from the way traffic lights have been operated for more than a century. Most cities, he says, set their traffic systems manually by doing traffic counts at different times of the day and then creating timing plans that control when the light turns red or green. Few have the ability to be more precise, and many leave these timing plans in place for years. “The recommendation from the FHWA is to do retiming every three to five years,” he says.
NoTraffic offers what Kreisler calls a real-time approach to traffic light timing. The system works through a network of AI-enabled cameras mounted at signalized intersections. The cameras can detect all kind of road users, including cars, cyclists, and pedestrians, and this data is used to adjust the cycle time of each intersection’s traffic light changes. If a gaggle of schoolkids is crossing the road, the system will keep cars at a red light longer. If a swell of cars is approaching the intersection, the system can extend their green light instead of cutting off the back half of the pack with a red.
Kreisler estimates that 90% of signalized intersections around the world are operating on fixed timing systems—a green-yellow-red cycle every two minutes during rush hour, every four minutes in the middle of the night, for example. These fixed times make sense in the abstract, but don’t really respond to actual dynamic conditions on the road when, say, a local school lets out early or a nearby road is blocked for construction. NoTraffic’s technology can automatically adjust the timing of lights to accommodate these kinds of changes.
The technology has been installed in traffic light systems in cities like Palo Alto and Redlands, California, and a few cities in the Phoenix area.
Its presence in Chandler, Arizona, hints at how NoTraffic sees its market expanding. Chandler is an emerging center of autonomous vehicle technology development and home to one of the first citywide implementations of a street-legal, passenger-carrying autonomous vehicle fleet, operated by Waymo. NoTraffic’s system is set up to interact directly with autonomous vehicles outfitted with increasingly common built-in vehicle-to-infrastructure communication technology. This technology—which car companies like Audi and Volvo are using to improve the ways cars detect and avoid collisions with cyclists and pedestrians—is becoming a new standard in auto manufacturing. The U.S. Department of Transportation says these vehicle-to-everything communication systems “have the potential for significant transportation safety and mobility benefits.”
But it’s not just turning streets into relentless autobahns of speeding cars. The system can also be used to identify potential red light runners, and issue warnings to cars in the area with these communication systems built in. For now, the majority of vehicles on the road don’t have these systems.
Even so, NoTraffic’s technology can change the way traffic moves through cities, making green lights last longer for transit, for example, or even prioritizing electric vehicles over gas guzzlers.
“We’ve been asked to do light rail. We’ve been asked to do snow plows,” Kreisler says. “The only thing you need to do is retrain the algorithm to detect this class of vehicle and define the level of priority.”
That doesn’t necessarily mean cities will use the technology to make their streets safer. Traffic congestion is one of the main issues residents complain about to city leaders, and many make solving traffic issues a key promise. A system like NoTraffic could be set to give pedestrians more time crossing the street, or it could prioritize giving drivers as many green lights as possible.
Kreisler says it’s up to officials how to use the technology. “We’re not defining policy,” he says. “We’re just enabling tools.”