Expanding London’s Low-Emissions Zone Led to Major Air Quality Improvements, Report Finds

The London ULEZ, or Ultra Low Emission Zone, expanded in August 2023 to cover all of London’s boroughs in order to reduce emissions and air pollution. The results? A significant drop in greenhouse gas emissions from traffic and improved air quality within the first six months of the expansion, a new report has confirmed.

According to the report, nitrogen oxide emissions from cars in outer London declined 13% with the expansion, and particulate matter emissions, or PM2.5, from cars and vans decreased around 20% in outer London since the expansion.

As The Guardian reported, the overall impact of the 2023 expansion of the ULEZ led to emissions reductions equivalent to taking around 200,000 cars off the roads.

“London’s air quality is improving at a faster rate than the rest of England, and 96% of vehicles are now compliant, with tens of thousands of Londoners benefitting from our scrappage scheme,” London Mayor Sadiq Khan said in a press release. “It’s thanks to our bold policies, including ULEZ, that we are now set to get London’s air to within legal limits by 2025, 184 years earlier than previously projected. But there’s still more to do and I promise to continue taking bold action — including more to clean up out air and rivers — as we build a fairer, greener London for everyone.”

The ULEZ was first implemented in 2019 and applied only to Central London. By 2021, it had been expanded further to the North Circular and South Circular Roads. In August last year, officials stretched the zone to cover greater London in order to promote transition to electric vehicles, the use of public transit, walking and cycling. Ultimately, the goal for the ULEZ is to help reduce emissions and allow the city to reach its target of net-zero emissions by 2030, Intelligent Transport reported.

So how does it work? The ULEZ operates 24/7, year-round, with the exception of December 25. Vehicles must meet the ULEZ requirements based on particular vehicle emissions, or qualify for exemptions. Otherwise, drivers pay £12.50 (about $16.10) per day to drive within the ULEZ limits, which now cover greater London. The money collected from ULEZ fees go toward maintenance and improvements for London’s transportation network. 

Meanwhile, the initiative encourages more people to switch to lower emissions vehicles and/or walk, bike, or take public transit, reducing traffic-related emissions within the city.

According to the recent report, vehicle compliance in the expanded ULEZ area is around 96.2%, while compliance in inner London is around 96.5% and central London is around 96.4%, meaning the vast majority of vehicles meet the low-emissions standards and do not have to pay fines.

“Improving air quality through initiatives like the Ultra Low Emission Zone in London is crucial for protecting public health and reducing the burden of disease,” Dr. Maria Neira, director of the Department of Environment, Climate Change and Health at the World Health Organization (WHO) said in a statement. “Cleaner air leads to healthier communities, lower rates of respiratory and cardiovascular illnesses, and a better quality of life for all residents. The World Health Organization commends the efforts of cities like London in implementing measures to reduce emissions from vehicles and improve air quality, which ultimately contribute to a healthier and more sustainable urban environment.”