London expands its successful ULEZ scheme


London (United Kingdom)

Challenge area:

Pollution Reduction

Implementation period:


London Big Ben and Busses

The Challenge

Despite recent improvements in air quality, toxic air pollution remains the biggest environmental risk to the health of all Londoners. Around half of London’s NOx emissions are from road transport. Reducing the amount of pollution from traffic remains one of the best ways of cleaning up air in London.

Around 4,000 Londoners died prematurely in 2019 because of long-term exposure to air pollution. It is a cause of cancer and increases the risk of asthma, stroke and dementia. Pollution is also stunting the growth of children’s lungs in ways that will affect them for the rest of their lives.

The purpose of the Ultra Low Emission Zone (ULEZ), introduced in April 2019, is to improve air quality in and around central London by reducing the number of older more polluting vehicles that enter the central zone. This will reduce the amount of NOx emitted, which in turn will reduce nitrogen dioxide (NO2) concentrations in the zone. Bringing London closer to compliance with the legal air quality limit values for NO2 is a key aim of the scheme.

In October 2021, the ULEZ was expanded to a much larger area of London, out to the North and South Circular roads, an area 18 times the size of the original central zone and home to 3.8 million people. With this expansion along with other measures implemented by the Mayor, London expects to meet legal limits for NO2 by 2025.


The Solution

In London ULEZ is co-ordinated by the government authority Transport for London (TfL). ULEZ operates 24/7 in inner London inside the North and South circular roads. Cars, motorcycles and vans under 3.5 tonnes need to meet the ULEZ emissions standards or their drivers must pay a daily charge to drive within the zone which is:

  • £12.50 for most vehicle types, including cars, motorcycles and vans (up to and including 3.5 tonnes)
  • The ULEZ standards for existing central London ULEZ and when the zone expands are:
  • Euro 3 for motorcycles, mopeds, motorised tricycles and quadricycles (L category)
  • Euro 4 (NOx) for petrol cars, vans, minibuses and other specialist vehicles
  • Euro 6 (NOx and PM) for diesel cars, vans and minibuses and other specialist vehicles

Vehicle compliance refers to the number of vehicles that “comply” or meet the ULEZ emission standards. The ULEZ has no barriers or toll booths. Instead, cameras read vehicle number plates and check it against a database of UK-registered and non UK-registered vehicles. This tells the governing authority whether the vehicle meets the ULEZ emissions standards, is exempt, is registered for a discount, or if you have already paid the daily charge.