Central London ULEZ - Ten Month Report

This report evaluates the impact of the central London Ultra Low Emission Zone (ULEZ) in its first ten months of operation.

Between February 2017 and February 2020, there has been a 39 micrograms per cubic metre reduction in roadside concentrations of nitrogen dioxide in the central zone, a reduction of 44 per cent.

In January 2020 the average compliance rate with the ULEZ standards was around 79 per cent in a 24 hour period (and 77 per cent in congestion charging hours). This is much higher than 39 per cent in February 2017 and the 61 per cent in March 2019 (congestion charging hours).