Air pollution is not just a central London problem, with many areas still exceeding the legal limits for pollution across the city. That is why from 25 October 2021, the central London Ultra Low Emission Zone (ULEZ) is expanding to create a single, larger zone up to the North Circular Road (A406) and South Circular Road (A205). The North and South Circular Roads themselves are not in the zone. This is part of the commitment by the Mayor and TfL to help every Londoner breathe cleaner air.