Google gives the green light to more AI-powered intersections

Time spent sitting in your car at a red light is more than just an annoyance—it’s also terrible for the environment.

That’s why Google is out to prove that AI can help make a dent in those idle periods by coordinating stoplights more efficiently. Two years after it first debuted Project Green Light, the tech giant said initial results show the effort has the potential to reduce stops by 30% and cut emissions at intersections by 10%.

Google has since expanded the program to a dozen cities across four continents, including Seattle, Rio de Janeiro, Hamburg, and Jakarta, and plans to add more next year.

In a 2015 study, scientists estimated that city intersections tend to harbor around 29 times more pollution than the open road. That extra pollution—not to mention the headaches that traffic snarls cause city planners—led to a growing field of research around smarter intersections that make use of tech like AI.

Among these efforts, Google’s project has the advantages of being free and easy for city engineers to implement—the company claims it takes “as little as five minutes” to set up. The company also has the added benefit of reams of Google Maps data on the daily ebbs and flows of cars in roadways everywhere.

Google claims Project Green Light works by using information from Maps and AI to “model traffic patterns and make recommendations for optimizing the existing traffic light plans.” The company is also able to coordinate across nearby intersections to create better flow across wider areas, and then present its recommendations to city engineers through the program’s interface.

“As an example, we might identify an opportunity to coordinate between intersections that are not yet synced and provide a recommendation around the timing of the traffic lights so that traffic flows more effectively along a stretch of road,” Yossi Matias, Google’s VP of engineering and research, wrote in the blog post.

Smarter traffic lights are just one piece of how Google thinks data gleaned from Maps can help drive sustainability initiatives. The company previously rolled out a set of APIs to give developers more information on environmental threats like wildfires, heat waves, and solar power potential.