ULEZ ‘not making much difference’

IMPERIAL COLLEGE STUDY SUGGESTS CONTROVERSIAL SCHEME IS ‘NOT EFFECTIVE’

THE Ultra Low Emission Zone (ULEZ), which was introduced to help tackle air pollution in London, caused “only small improvements” in air quality on its introduction, a study has revealed.

The study, from Imperial College London, found the biggest improvements in air quality in the capital actually happened before the ULEZ was introduced in 2019.

Researchers said this suggests the ULEZ is “not an effective strategy to improve air quality.”

Researchers from Imperial College London compared publicly available air quality data from roadside and non-roadside air quality monitors across London over a 12-week period before and after the introduction of the ULEZ in 2019.

They discovered only small improvements in air quality after the ULEZ started.

These included an average reduction of less than 3 per cent for nitrogen dioxide concentrations, as well as “insignificant effects” on ozone and particulate matter (PM2.5) concentrations.

Researchers noticed that changes in air pollution varied significantly across the monitoring sites, and at some sites, the pollution actually got worse.

By contrast, the number of Londoners living in areas with illegally high levels of nitrogen dioxide fell by 94 per cent between 2016 and 2020.

The bottom line was that the ULEZ on its own is not enough to tackle air quality issues and, instead, a variety of clean air measures are needed.

Dr Marc Stettler, corresponding author of the research from Imperial’s Department of Civil and Environmental Engineering and Centre for Transport Studies, said: “The case of London shows us that it works best when combined with a broader set of policies that reduce emissions across sectors like bus and taxi retrofitting, support for active and public transport, and other policies on polluting vehicles.”

City Hall disagreed with the findings. Shirley Rodrigues, deputy mayor for environment and energy, said: “This study is very misleading and its findings have been queried by experts within the university.

“Imperial College’s world-leading Environmental Research Group have been clear that the ULEZ has had a significant and positive effect on air pollution. The ULEZ has already helped cut toxic roadside nitrogen dioxide pollution by nearly half and led to reductions that are five times greater than the national average.”

City Hall analysis, independently peer reviewed by Dr Gary Fuller at Imperial College London, showed that the reduction in NO2 concentrations at roadside locations in central London directly attributable to the ULEZ was 37%, compared to a scenario where there was no ULEZ.

City Hall noted that the full benefits of ULEZ require a look at a longer time period – at least a year.