Hangzhou ET City Brain — China's AI platform for smart city governance and traffic management

Launched in 2017 as a joint initiative between the Hangzhou Municipal Government and Alibaba Cloud, ET City Brain integrates feeds from over 4,500 traffic cameras, traffic sensors, and emergency dispatch systems across the city's road network in Hangzhou, China. The platform uses computer vision and machine learning to dynamically adjust traffic signal timing, detect incidents such as accidents or stalled vehicles, and pre-clear routes for ambulances and fire trucks. By 2019 the system had expanded to more than 15 Chinese cities and to Kuala Lumpur, Malaysia, with an upgraded City Brain 3.0 released in March 2025.

The platform aims to reduce urban traffic congestion and improve emergency response by using computer vision and machine learning to dynamically adjust traffic signals, detect incidents in real time, and pre-clear routes for emergency vehicles.

ET City Brain integrates live feeds from more than 4,500 traffic cameras, sensors, and emergency dispatch systems, using AI to dynamically retime traffic signals, detect incidents such as accidents or stalled vehicles, and pre-clear routes for ambulances and fire trucks across the city's road network.

A peer-reviewed paper in IET Smart Cities (2019) reported that by 2018 average vehicle speeds on the pilot corridor had increased by 15%, and that Hangzhou's congestion ranking among Chinese cities fell from 5th to 57th place by 2020. Ambulance response times in covered districts dropped by approximately 50%.

The reported gains come mainly from a single peer-reviewed study of one pilot corridor and city-level congestion rankings; despite this limited evaluation scope, the platform has continued to expand, reaching more than 15 Chinese cities and one international deployment, with a third-generation version (City Brain 3.0) released in 2025.