April 12, 2019—The Ultra-Low Emission Zone will operate in central London 24-hours a day, seven days a week moving forward, reported CNBC.

The ULEZ is built around “Euro Standards.” A framework introduced in 1992, the standards encompass emissions controls which set limitations for nitrogen oxides and particulate matter from a vehicle’s engine. 

Gas vehicles that do not meet Euro 4 standards and diesel vehicles that do not meet Euro 6 standards will have to pay the daily £12.50 ($16.32) ULEZ charge in addition to the existing similar congestion charge.

Approximately 50 percent of air pollution comes from road transportation and 45 percent comes from diesel, according to the report.