São Paulo adopts Google’s AI to improve green and red traffic light times

The city of São Paulo (SP) is the new partner of Green Light, Google’s project that employs artificial intelligence to optimize the timing of traffic lights. Announced during Google for Brazil 2026 and developed in partnership with Prodam, the city’s technology company, and with technical support from the Traffic Engineering Company (CET), the technology analyzes circulation patterns to reduce unnecessary stops, improve the flow of vehicles, and reduce fuel consumption and CO2 emissions. The capital becomes the fourth Brazilian city to adopt the system — and the one with the largest fleet in the country, with about 9.9 million vehicles.

Green Light does not take control of traffic lights. Based on traffic data collected by platforms such as Google Maps and Waze, the algorithms identify circulation patterns at each intersection and calculate adjustments capable of reducing stops — often differences of a few seconds in the time for the signals to open. The recommendations are forwarded to CET’s technical team, which analyzes, tests and decides whether the changes will be implemented. Thus, the final decision remains with the traffic managers, a human layer that the company considers essential.

According to Google, cities that have already adopted the project have the potential to reduce vehicle stops by about 30% and emissions by more than 10% at optimized intersections. In Brazil, where the technology adds up to 83 intersections, the company points to a 9% drop in fuel consumption. In São Paulo, the first results pointed out by CET indicate a decrease of close to 10% in stops at some of the participating intersections – a percentage considered relevant in view of the enormous volume of traffic in the city.

“We are using AI as a powerful tool to make traffic more fluid and air cleaner,” said Paula Aluani, Google’s partnership manager for Maps and Waze in Latin America, noting that the gains come without the need to build new infrastructure. The collaboration was formalized by a memorandum of understanding signed this year between Prodam and Google.

Launched globally in 2023, Green Light debuted in Brazil in Rio de Janeiro and had already passed through Campinas and São Caetano do Sul before arriving in São Paulo. Worldwide, the initiative is present in more than ten cities spread across four continents, such as Seattle, Hamburg and Jakarta. For now, the system operates at a selected set of intersections in the capital, and the expectation is to gradually expand coverage as the data accumulates.