London motorists driving older, more polluting vehicles must pay a new charge from Monday as part of one of the world's toughest vehicle emissions programmes.
The ultra-low emission zone (Ulez) charges certain polluting vehicles a 12.50 pounds ($16, 14.5 euros) fee to enter the centre of the British capital under mayor Sadiq Khan's plans to reduce air pollution.
Anyone driving a diesel cars more than around four years old and a petrol cars more than around 13 years old will pay the charge, although the vehicle's declared emissions will be the official measure.
Black cabs are exempt from the charge.
Larger vehicles, such as lorries and coaches, that exceed the limits face a daily charge of 100 pounds.
Khan said the Ulez will "help clean our air and reduce harmful road transport emissions", which "shorten life expectancy and damage lung development."
"This study is a stark reminder that air pollution disproportionately affects the most vulnerable Londoners and I'm doing everything in my power to protect children, the elderly and those with respiratory conditions from our filthy air."