# London's clean air zone

By [Brandon Donnelly](https://brandondonnelly.com) · 2024-09-24

central-london, clean-air-zone, congestion-charge, environment, london, mobility, nitrogen-dioxide, politics, sadiq-khan, ulez, ultra-low-emission-zone, urbanism, vehicle-traffic

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In 2019, London implemented something known as an [Ultra-Low Emission Zone (or ULEZ)](https://tfl.gov.uk/modes/driving/ultra-low-emission-zone). The intent was to reduce the number of older and higher-polluting vehicles entering and driving around the city.

It works like this: If you have a vehicle that does not meet the ULEZ emission standards, you need to pay a daily charge of £12.50. This applies all day every day (except Christmas) and it is _in addition_ to London's congestion charge.

It's also done entirely through license plate cameras. If you enter the zone, don't have an approved plate, and don't pay the charge within a few days, you get sent a fine. The result is that London's ULEZ is now the largest clean air zone in the world ([at least according to London](https://www.london.gov.uk/programmes-strategies/environment-and-climate-change/pollution-and-air-quality/ultra-low-emission-zone-ulez-london#:~:text=Drivers%20of%20vehicles%20that%20don,Christmas%20Day%20\(25%20December\).)).

It also achieved its intended purpose. In 2017, only 39% of cars entering London would have met the ULEZ emission standards. Today the number is over 95%. Meaning, most people don't actually pay the charge.

At the same time, nitrogen dioxide levels in the zone have more than halved, improving overall health outcomes. It's a perfect example of taxing the things you want less of. What's also interesting is that there were positive second-order consequences.

Vehicle traffic as a whole declined by about 9% in the first year, with no evidence of displacement to other areas. And according to [this research study](https://ijbnpa.biomedcentral.com/articles/10.1186/s12966-024-01621-7), it actually encouraged more kids to walk and take other forms of "active transport" to and from school.

Seems like a no brainer to me.

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*Originally published on [Brandon Donnelly](https://brandondonnelly.com/londons-clean-air-zone)*