London Mayor Sadiq Khan has asked officials to look into introducing more days when cars are not allowed on certain roads or in specific areas as the city considers new ways to cut pollution.
Khan has already introduced an additional charge on the most gas-guzzling vehicles entering central London and has brought forward the introduction of an ultra-low emission zone.
"The Mayor already supports a number of car-restricted days for annual events in London, and he has asked City Hall officials to consider additional opportunities for car-free activities as part of his Healthy Streets vision," his office said.
"The Mayor is determined to do everything in his power to protect the health of Londoners and prioritise walking, cycling and public transport and reduce Londoners' dependency on polluting cars."
Cities and nations around the world are planning to restrict or ban the use of diesel and petrol vehicles in the years ahead and promote greener technologies in a bid to improve air quality.