If you ask the council about the Clean Air Zone (CAZ), it will highlight a huge impact on air pollution across the city—between 2023 to 2024, average nitrogen dioxide (NO₂) concentrations fell by 5.1% inside the CAZ, while areas outside saw a 4.4% decrease.
“Air pollution is one of the most significant environmental risks to our health,” said Councillor Martin Fodor, Chair of the Environment and Sustainability Committee. “Cleaner air means healthier lives, especially for our most vulnerable residents such as children, older people, and those with respiratory conditions.
“The Clean Air Zone is continuing to deliver real improvements to Bristol’s air quality, and the latest figures show that we are moving in the right direction, not just inside the CAZ but across the whole city as, on average, areas outside the zone have also seen a reduction in air pollution.”
The CAZ is a daily charge for vehicles passing through the zone that are above the minimum emissions standards. This £9 charge is to discourage journeys in non-compliant vehicles to improve air quality—with any additional income generated put directly back into Bristol’s transport infrastructure.
Bus services, highway maintenance, and parking schemes have all benefited from the introduction of CAZ. But that doesn’t mean it hasn’t come with its controversy. Ask a random person on the street, and you may be in for a rant about it being a “rip-off” or a “scam”, although financial assistance schemes are available for residents to upgrade their vehicles.
Who does Bristol’s Clean Air Zone affect?
More than 71% of vehicles going into Bristol already meet the air quality rules. Only older, pollution-unfriendly vehicles will need to pay the charge. The CAZ charges do not apply to Euro 4, 5, and 6 petrol vehicles (those registered from 2006 upwards) or Euro 6 diesel vehicles (those registered from late-2015 onwards). Check your vehicle here.
What’s changing?
Smaller reductions in NO₂ in 2024 than in 2023 suggest that current charges may no longer act as a strong enough deterrent. A proposal has been put forward to adjust CAZ charges in line with inflation, either to £10 (reflecting inflation since the CAZ launch in 2022), £12 (based on inflation since the charges were agreed in 2019), or £14 (above inflation).
Provisional modelling results show that a reduced number of non-compliant vehicles enter the CAZ zone in all increased scenarios. The higher the charge rate, the bigger the deterrent. Before any increase in CAZ charges, a public consultation would be necessary before any changes are implemented.
While Bristol City Council has introduced electric buses to help with air pollution, without a rise in fees, it’s believed that NO₂ levels won’t fall below legal limits in some parts of the city centre (40 micrograms per cubic metre) until 2029. High levels of air pollution can contribute massively to serious health issues.