Air pollution in the Western Extension Zone (4)

MQT on 2010-06-09
Session date: 
June 9, 2010
Question By: 
Mike Tuffrey
Liberal Democrats
Asked Of: 
The Mayor


What exactly is meant in the latest consultation document about the removal of the western extension of the congestion charging zone (WEZ) when it says 'there would be no measurable deterioration of air quality if the WEZ is removed' (eg does TfL expect, say, a 3% average annual increase in PM10 concentrations across the entire WEZ area which might, perhaps, be offset by mild and wet weather conditions and therefore be hard to measure)? Like for like, by what percentage are annual mean concentrations of PM10 likely to rise in the most polluted part of Brompton Road if the WEZ is removed?


Answer for Air pollution in the Western Extension Zone (4)

Answer for Air pollution in the Western Extension Zone (4)

Answered By: 
The Mayor

The primary focus of the Congestion Charging scheme has always been to tackle congestion and reduce traffic. Related reductions in the emissions of air pollutants from vehicles in the zone have been welcomed, but have been comparatively small and have not resulted in direct measurable improvements in air quality because of the effect of other factors. Correspondingly although TfL estimates that emissions of PM10 from traffic in the Western Extension might increase by some 3.5% and emissions of NOx by some 2%, the removal of the zone would not be expected to result in a measurable deterioration of air quality.

Based on TfL's modelling, the maximum percentage increase in annual mean PM10 concentrations on Brompton Road is predicted to be 3.6% occurring at the junction of Brompton Road and Knightsbridge.

Should the Western Extension Zone be removed, pollutant concentrations within the western extension area will continue to be monitored in order to determine changes in air quality. Should monitoring show that the removal of the WEZ is having a detrimental impact on local air quality, TfL will look to implement targeted local mitigating measures.