Covering the entire length of the M4/A4 western “cut out” of the ULEZ October 2021 expansion (‘the unprotected banana’), and areas covered by the Chiswick and Hammersmith Air Quality Focus Areas, the hedge would run along both sides of the A4 from Chiswick roundabout to the Hammersmith flyover.

The ULEZ and ULEZ Expansion

The Central London Ultra Low Emission Zone (ULEZ) came into force on 8th April 2019. It imposed a £12.50-a-day charge to drive into central London in all but the cleanest cars and vans. The move is expected to reduce road transport emissions in the zone by around 45%.

From 25 October 2021 the ULEZ boundary will be extended to create a single larger zone bounded by the North and South Circular Roads. Any petrol or diesel vehicle within this enlarged area will also need to meet new tighter emissions standards or pay a daily charge.

The expanded ULEZ boundary has a strange "cut out" along the A4 Great West Road. Our Great West Hedge proposal is designed to address this gap in protection.

The Chiswick and Hammersmith Air Quality Focus Areas

These maps from the Mayor of London’s Green Infrastructure Map show the proposed hedge in relation to:

  • Air Quality (PM2.5) (hexagons)
  • The Air Quality Focus Areas (yellow rectangles)

The hexagons show the Air Quality (PM2.5), with lighter colours indicating higher values.

Scores along the A4 range from 0.42 to 0.55 versus a threshold of 0.34 defined by the World Health Organisation threshold of 10.00ug/m3 for health effects.

The yellow rectangles define London Atmospheric Emissions Inventory (LAEI) 2010 Air Quality Focus Areas. These are locations that not only exceed the EU annual mean limit value for NO2 but are also locations with high human exposure. The Focus Areas were defined to address concerns raised by boroughs within the LAQM review process and forecasted air pollution trends. This is not an exhaustive list of London’s hotspot locations, but where the GLA believe the problem to be most acute.

The green lines shows the proposed general extent of the Great West Hedge.

Schools and Nurseries exceeding NO2 Legal Limit

The Mayor of London Air Quality map highlights schools along the Great West Road which exceed the NO2 Legal Limits, marked with red dots in the below.