Commuters in Santiago, Chile, spend over 100 hours each year idling at traffic lights—fueling both congestion and emissions. Now, the city is turning to artificial intelligence for relief.
Santiago has joined 15 global cities in deploying Google’s Green Light project, an AI-powered system that optimizes traffic signal timing to reduce stop-and-go driving. Backed by real-time data from Google Maps and Waze, the system identifies congestion hotspots and recommends adjustments to traffic light patterns—cutting unnecessary stops by up to 30% and slashing intersection-related CO₂ emissions by 10%.
The initiative arrives at a critical time. Santiago ranks 126th globally for traffic congestion, according to the TomTom Traffic Index 2024. A typical 10-kilometer trip in the city involves more than 23 minutes spent at red lights, a major contributor to vehicle emissions. Globally, transportation accounts for around 15% of greenhouse gas emissions.
Developed by Google Research, Green Light emerged from a simple observation. “We explored various ideas, and my wife pointed out how much time is wasted at traffic lights,” said Dotan Emanuel, a software engineer at Google Research.
The system integrates mobility data with traffic signal locations to pinpoint inefficiencies. In Santiago, AI-generated insights are sent directly to the city’s Traffic Control Operations Unit (UOCT), allowing engineers to make real-time signal adjustments—without requiring new infrastructure.
Since launching in 2021, Green Light has been rolled out in cities including Manchester, Hamburg, Rio de Janeiro, Seattle, and Boston. With more than 30 million trips managed each month, the technology is proving to be a scalable, cost-effective way to improve urban traffic and environmental outcomes.
In Santiago, 10 intersections have already been upgraded through a collaboration with Chile’s Ministry of Transport and Telecommunications. “This project demonstrates how technology can significantly impact the fight against climate change,” said Frías, a lead official on the project.
As urban centers face mounting climate and mobility challenges, Santiago’s adoption of AI-powered traffic control signals a growing trend toward digital solutions that improve both commute times and air quality—paving the way for smarter, greener cities worldwide.
