Quebec City using artificial intelligence to manage traffic, reduce congestion

Quebec City has started synchronizing traffic lights with the use of Google’s artificial intelligence, technology the city says will improve traffic flow, reduce congestion, and lower greenhouse gas emissions.

According to Google Canada, Quebec City is the first municipality in the country to partner with the web giant’s Green Light project, which the company offers free of charge to cities.

“The Green Light project uses driving trends from Google Maps and artificial intelligence to map a city’s traffic patterns and then make specific recommendations for specific intersections that can be implemented very quickly by city engineers,” said Laurence Therrien, public affairs manager at Google Canada.

She noted that the AI model does not replace the work of engineers, but is an additional tool.

“The aggregated and anonymized trends from Google Maps really give a much faster and more reliable overview of a city’s traffic than if it had to be done manually or with existing systems,” Therrien said.

Including in Quebec City, the Green Light project is being used in 19 cities on four continents.

Google has analyzed traffic data in these cities, and said the project has “demonstrated the potential to reduce frequent stops and starts by up to 30 per cent and estimated (carbon dioxide) emissions at urban intersections by 10 per cent.”

Therrien says it’s “not necessarily” true that people will flock to cars if a city’s traffic flow improves. “If car traffic flows more smoothly, so does bus traffic,” she said. “So it encourages public transportation, which is much more efficient than if traffic lights are not automated.”

In Quebec City, the project has already made it possible to adjust the timing of traffic lights at 11 intersections, and the initial results are positive, according to Mayor Bruno Marchand.

“An innovative project like Green Light allows us to quickly and effectively optimize our road network, thereby improving traffic flow and efficiency,” said Marchand in a news release on Monday.

The release noted that during the evening rush hour, traffic lights were “slightly out of sync” near a busy intersection, causing delays and traffic jams. “Using the Green Light AI model, Google proposed reducing the gap between the lights by 15 seconds to align them (with the other intersection),” leading to smoother and better co-ordinated travel.

That example shows how AI “can complement the work of municipal experts by proposing simple, effective, and data-driven adjustments,” the city noted.

This report by The Canadian Press was first published Aug. 19, 2025.

Stéphane Blais, The Canadian Press