London mayor Sadiq Khan has welcomed new data showing that compliance rates in the new outer London part of the Ultra Low Emission Zone (ULEZ) have nearly caught up with those in inner London.

The ULEZ, which charges some drivers of vehicles that do not meet emissions standards £12.50 a day to drive in the zone, was controversially expanded at the end of August to cover the whole of London.

A report released by City Hall on Tuesday shows that the London-wide compliance rate for vehicles subject to the ULEZ standards during the first month was 95.3%, up from 91.6% in June.

The number of non-compliant vehicles seen driving in London on an average day has decreased by 77,000 (45%) compared to June 2023, while outer London has seen a 10 percentage point increase in compliance since the launch of the consultation on expanding the scheme.

At the start of the consultation in May last year, 85% of vehicles in outer London on an average day were compliant, which had increased to 90.9% by June.

Mr Khan said: ‘This data is a testament to the huge progress we’ve made in tackling toxic air pollution since I was first elected in 2016. Londoners are experiencing a greener, cleaner, and healthier city.’

City Hall said that after just one month, compliance rates across all vehicle types in outer London have nearly caught up with inner London. The current compliance rate for cars in outer London is 96.4%, compared to 96.9% in inner London.

However, van compliance in outer London is much lower at 86.2%, up from 79.5% in June.

City Hall said that only a small proportion (2.9%) of all vehicles covered by ULEZ paid the charge on an average day, with 1.7% non-chargeable, including those registered for a discount or exemption, and 0.2% issued with a warning notice or, from 26 September, a penalty charge notice.

Of the approximately 93,700 non-compliant vehicles on an average day London-wide, 57,200 (61%) paid the £12.50 charge, bringing in approximately £22.2m a month, which is more than double the London-wide revenue before the scheme was expanded.

City Hall said any net revenue raised through the ULEZ is being 'reinvested' into public transport such as in expanding the Superloop but network in outer London and that by the 2026/2027 financial year the scheme is expected not to raise any net revenue as the percentage of compliant vehicles continues to rise.

This article first appeared on Transport Network.

For more on ULEZ, check out our feature: 'Now I am become Uxbridge, destroyer of rational climate discourse'