Lockdowns Tamed Road Traffic. Here’s How Cities Aim to Keep It Down.

As coronavirus lockdowns loosen around the world, city leaders are scrambling to address a new problem: the prospect of gridlock worse than before the pandemic. From Shenzhen to Milan to Austin, officials are trying to coax people back onto buses and subways and reclaim road space for cyclists and pedestrians.

In many cities, officials worry that people will avoid public transit for fear of catching the virus, and decide to drive instead, which will push vehicle traffic higher than ever. Staving off a surge of cars on city streets is important not only to avoid congestion delays, accidents and higher air pollution, which kills an estimated four million people worldwide each year. It’s impossible to stop global warming unless cities sharply reduce pollution from cars, trucks and motorcycles.

“Cities have a window of opportunity to make changes and keep the cleaner air they saw during the lockdowns,” said Corinne Le Quéré, a climate scientist at the University of East Anglia who has tracked global carbon dioxide emissions during the pandemic. “But if they don’t pay attention to this issue, emissions could rebound back to where they were before or even go higher.”

Transportation accounts for a quarter of the world’s carbon dioxide emissions, and emissions from road vehicles in particular have grown sharply in the last 50 years.