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FOI - Air quality before the introduction of the ULEZ [Feb 2023]

Key information

Request reference number: MGLA130223-9958

Date of response:

Summary of request

Your request

  1. What was the mean average air pollution caused by motor vehicles across the whole of Greater London before the introduction of the Ultra Low Emission Zone (ULEZ)?
  2. What the actual figure is now, not the ‘projected’ figure.
  3. What the projected level would be today, had the ULEZ not been implemented.
  4. Was the mean westerly airflow across the capital taken into account when these statistics were compiled?

Our response

The GLA regularly reports on the air quality and vehicle reduction impacts of the ULEZ.

This reporting uses data from the city’s air quality monitoring network to analyse the long term trends in pollution concentrations as well as estimating the impacts of the scheme.

The reports include a detailed description of the methods used to evaluate the impact of the ULEZ and have been peer reviewed.

Figure 15 of the report shows the trend in monthly average nitrogen dioxide (NO2) concentrations from January 2010 to October 2022. Table 14 provides the quarterly average NO2 concentrations at different site types and locations and the reduction compared to 2017 when the ULEZ expansion plan was first announced.

If you have any further questions relating to this matter, please contact us, quoting 
reference MGLA130223-9958.

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