Use the ULEZ to improve air quality and reduce pollution

Description: In 2003, London made history by becoming the first city after Singapore to introduce congestion pricing for vehicles entering the Congestion Charge Zone in Central London. Following initial implementation in 2003, the congestion pricing program has been modified several times. While studies showed that the Congestion Charge initially succeeded in reducing London traffic, over time it resulted in increased bus, delivery van, and taxi traffic with the majority of these vehicles powered by diesel engines that contributed to the already poor air quality of London. Furthermore, increasing use of ride hailing services also eroded some of the early reductions in traffic congestion achieved by the Congestion Charge. The result was that many argued that the Congestion Charge had become obsolete in its current form and needed to be revised or replaced.

Mayor Sadiq Khan, elected in 2016, outlined a bold strategy to make London the greenest global city by investing in infrastructure that enabled more walking and biking while simultaneously reducing the use of polluting vehicles. The Ultra Low Emission Zone (ULEZ) was launched in April 2019 in an effort to minimize dependence on polluting vehicles, help combat air pollution, and accelerate progress toward the Mayor’s goal of net zero carbon emissions by 2030. The ULEZ initially covered the same area as the Congestion Charge Zone in Central London and in October 2021 was expanded to include all areas inside the North and South Circular roads; it now covers a quarter of London and 3.8 million people.

In the ULEZ, which is in operation 24 hours a day and 7 days a week with the exception of Christmas Day, most vehicles that fail to meet a specific set of emissions standards must pay a daily charge of £12.50 (the equivalent of about $17.20). Non-compliant vehicles driving within the ULEZ without a specific exemption or those failing to pay the daily charge must pay a penalty fee of £160 (or £80 if the fee is paid within 14 days). These charges are in addition to the £15 daily Congestion Charge.

Since 2017 London has provided over £60 million, in several different programs, to ease the burden on low-income and disabled residents, taxi cab and minibus owners, as well as small businesses making a switch to ultra low emission vehicles. Revenue generated by the ULEZ and other charging policies (e.g., Low Emission Zone and Congestion Zone regulations) will be reinvested into London’s public transit system.


  • Reduce toxic emissions, including nitrous oxides, carbon dioxide, particulates (PM2.5), and other air pollution within the ULEZ to improve air quality.
  • Expand low-emission public transport and non-motorized mobility options.
  • Encourage residents and businesses to switch to cleaner vehicles, public transport, or walking and cycling by establishing the world’s toughest driver-pays low emission zone.
  • Accelerate the shift to ultra-low emission vehicles by providing subsidies to low-income and disabled residents, as well as small business owners and targeted larger businesses, to scrap older polluting vehicles.


  • Airborne concentrations of nitrogen dioxide, carbon dioxide, and particulates
  • Number of older, more polluting, non-compliant vehicles that enter the ULEZ daily
  • Number of buses that meet or exceed the cleanest Euro VI emissions standards

Time to Implement:

  • 18 years of ambitious road user charging policies
  • 2 years from the announcement of plans for the ULEZ in 2017 until implementation in 2019


London Assembly – The Mayor’s Ultra Low Emission Zone for London

CNBC – London expands its ultra-low emission zone in bid to reduce air pollution

Central London Ultra Low Emission Zone – 2020 Report

London Net Zero by 2030: an Updated Pathway

Additional Information:
Air pollution is a serious global problem. Worldwide, 4.2 million deaths happen each year as a result of ambient air pollution exposure and in London specifically, around 4,000 people died prematurely in 2019 due to air pollution exposure. Air pollution can cause or increase the risk of many health problems, including cancer, asthma, stroke, and dementia, and it can stunt the growth of children’s lungs.

According to one study, the ULEZ on its own is not an effective strategy to combat air pollution; however, as one of many implemented policies, London has seen observable improvements in air quality. The ULEZ has contributed to a 44% reduction in nitrogen dioxide in the first ten months and prevented about 12,300 tons of carbon dioxide emissions. Illegal nitrogen dioxide levels were reduced so that 94% fewer people are now living in areas with illegal air quality and 97% fewer primary and secondary schools are now within areas exceeding legal pollution limits (from 455 in 2016 to 14 in 2019). There are also 44,100 fewer polluting cars driving in the ULEZ since the mayor announced the plans in 2017.

In addition, the European Commision, EU’s executive arm, has a goal to reduce carbon dioxide emissions from cars and vans by 100% by 2035. The ULEZ will help meet this goal.

Prize for Cities – London’s Ultra Low Emission Zone

AutoExpress – London ULEZ: London Ultra Low Emissions Zone explained

Imperial College London – London pollution has improved with evidence for small initial ULEZ effect

IOP Science – Has the Ultra Low Emission Zone in London Improved Air Quality?

Bloomberg CityLab – What Comes After London’s Congestion Charge?

Contact Info:

Sadiq Khan
Mayor of London
020 7983 4000

Sectors(s) Equity, Transportation & Land Use
Location(s) , , , , ,
Date First Adopted Central London plans announced in 2017 and implemented in April 2019. Expanded from Central London up to (but not including) the North Circular and South Circular roads on October 25th, 2021.
Last Updated March 17, 2022
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