Last reviewed 9 February 2021

The main bus network in London now exclusively uses Euro VI or cleaner buses, the emissions standard required by the Ultra Low Emission Zone (ULEZ).

Transport for London (TfL) said that its core bus fleet of 9000 vehicles meets the standard with only meal relief buses, training buses and some school buses put on as a response to the pandemic to enable social distancing included in this total.

Around £85 million has been invested in retrofitting older diesel buses to meet or exceed the Euro VI emissions standards since 2017.

Each retrofitted bus emits up to 95% less NOx emissions and 80% less particulate matter (PM) than before, leading to significant air quality improvements across the capital.

More than 400 all-electric buses have been introduced — including the UK's first full routes of electric double decker buses — and around 300 additional zero-emission buses are expected to join the fleet by the end of this year.

Claire Mann, Director of Bus Operations at TfL, said that the programme has made its diesel buses as clean as they can be, but she is determined to go further.

“We will press ahead with our electrification programme and investments in other green technology to ensure all buses in London are zero emission by 2037 or hopefully, if additional financial support can be found, sooner,” she concluded.