Google said it will use map data to help cities optimize traffic signals. Through its Maps app, Google has access to vast amounts of daily traffic data and uses it to provide cities with free AI-optimized traffic signal timing recommendations that can reduce stop/start times by 30% and reduce intersection emissions by 10%.

To date, Project Green Light has worked with 12 cities around the world to provide timing advice for 70 different intersections. The company says it will take just five minutes to roll out the changes, leveraging the city's existing management systems.

Data is one of the keys; urban traffic engineers simply don't have access to as extensive and high-quality information as Google, which has so many Android devices and in-car navigation systems online and constantly reporting location data.

Another reason is that the Google research team has artificial intelligence tools and expertise. They built a system that uses artificial intelligence and map data to build models of individual intersections and their traffic signals and patterns. They then extend these models to other intersections in the same area to achieve optimal synchronization and ensure vehicle movement.

Traffic engineers receive simple timing change recommendations they can implement using existing systems Figure/Google Research

The tool models and analyzes thousands of intersections simultaneously to create a city-wide map of traffic flow and conduct virtual experiments to bring a "green wave" to as many drivers as possible, thereby reducing traffic times, fuel consumption and emissions.

"Early data suggests a potential 30% reduction in parking times and a 10% reduction in greenhouse gas emissions," the project website reads. Of course, this is only for emissions at a single intersection, not for the city as a whole. But this approach could really make a difference once rolled out on a large scale.

The first cities to trial the Green Light Program include Rio de Janeiro, Seattle, Hamburg, Bangalore, Haifa, Budapest, Kolkata, Abu Dhabi, Hyderabad, Manchester, Bali and Jakarta. Google says the 70 intersections currently being trialled have the potential to impact approximately 30 million car trips per month.

David Atkin, manager of analysis and reporting at Transport for Greater Manchester, said: "Green Lights" uncovered opportunities that we were previously unaware of and led engineers to look at the possible benefits of changing signal timings. This provides valuable insights into our city of 2,400 traffic signals. Both the Green Light team and the Transport for Greater Manchester team bring expertise and ideas to improve travel and reduce emissions."

Google is inviting other cities to sign up on the wait list, and more will be added over time. Watch the video below.