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Cleaner air

Our members are committed to improving air quality, reducing congestion and dwell time to find parking spaces to support the government’s clean air strategy

Air pollution is the single greatest environmental risk to human health and transport emissions is a significant source of that pollution.  The immediate air quality challenge is to reduce emissions of nitrogen oxides in the areas where concentrations of these harmful gases currently exceed legal limits.  Reducing particulate matter or PM2.5 is also now a priority.

Clean Air Zones (CAZ) aim to reduce NO2 emissions in the worst effected areas.  There are two types of CAZ, one that is charged for and one that is not.  You may also recognise ULEZ – Ultra Low Emission Zone, which operate in London.

Local authorities are required to assess local air quality and develop an Air Quality Action Plan to reduce pollution to within statutory limits. Grant aid helps local authorities to implement the plan. Clean Air Zones are designed to tackle the most polluted spots. These are believed to be the best way to discourage polluting vehicles and encourage electric vehicle use as well as walking and cycling.

Parking contraventions in CAZs

Parking contravention Code 17 relates to on street parking (see the full list here) and is reserved for road user charging schemes and NOT specifically CAZs. However if a CAZ has a road user charging aspect then Code 17 would be applicable, with further localised definition. It is up to highways authorities to further define this Code.

Park Active

Improving our air quality also requires supporting additional initiatives and the implementation of other schemes that we support, such as ParkActive.

More information

We have collated a significant range of information to support our members to achieve cleaner air, which can be found in our Resource Library.

Want to be more active?  Our section on Active Travel may inspire you.

Types of Clean Air Zones

There are 4 types of Clean Air Zones, Class A to D. Class D is the only class that includes cars.

Class Vehicle type
A Buses, coaches, taxis, private hire vehicles
B Heavy goods vehicles, plus Class A vehicles
C Vans, minibuses, plus Class B vehicles
D Cars, plus Class C vehicles. Local authorities can also opt to include motorcycles

To avoid paying in a CAZ vehicles must meet minimum emissions standards:

Vehicle type Clean Air Zone minimum standard
Buses, coaches, heavy goods vehicles Euro VI
Vans, minibuses, taxis, private hire vehicles, cars   Euro 6 (diesel) and Euro 4 (petrol)
Motorcycles Euro 3


Latest developments on Clean Air Zones

This is the latest information on the implementation of CAZs in cities across England. See also a live map of the cities and areas where CAZs are being implemented or considered here.

Reducing Nitrogen Dioxide levels
The councils that have a duty to implement a full business plan to comply with legal limits of Nitrogen Dioxide in the shortest possible time, are listed here. The most recent councils are Coventry, Leeds and Southampton. 

Status of CAZs

Location Launch Class
Bath  Active March 2021 C
Birmingham Active June 2021 D
Portsmouth Active November 2021 B
Bradford 26 September 2022 C+
Bristol 28 November 2022 D
Greater Manchester Under review Under review
Tynside  30 January 2023 (TBC) C
Sheffield Early 2023 C


Four Low Emission Zones (LEZ) are in operation Glasgow, Edinburgh, Aberdeen and Dundee. These LEZs ban non-compliant vehicles, rather than charging for entry, and are therefore expected to have a fast and direct impact on emissions.

Air quality news

Climate-related mortality and hospital admissions, England & Wales 2001 to 2020
Office for National Statistics

World Health Organisation new air quality guidelines - recommends levels for 6 pollutants, where evidence has advanced the most on health effects from exposure; particulate matter (PM), ozone (O₃), nitrogen dioxide (NO₂) sulphur dioxide (SO₂) and carbon monoxide (CO). In turn each one of these impacts on other damaging pollutants. September 2021 here.

Air pollution shortens lives more than any other external cause Guardian Sept 2021 here

Government Transport Decarbonisation Plan published July 2021 here

Blog - The race to decarbonise transport is on and the parking sector is playing a key role here

Fleet News guide to the proposed CAZs here.

Government webpage on CAZs here.

Local authorities pay to use the CAZ Central Service no more frequently than every quarter 
See the Minister's response to question on the CAZ Central Service here.

Government has 'a long way to go' to meet emissions target from cars - report here.

Reducing air pollution could boost the UK economy - CBI commissioned by the Clean Air Fund says reducing air pollution could boost the UK economy by £1.6bn a year. Breathing life into the UK economy quantifies the economic benefit to the UK of meeting WHO Air Quality guidelines which are stricter than the current UK legal limits.  Things like a reduction in premature deaths, sickness absence and improved productivity at work would result from improved air quality.

Particulate Matter
Research reveals a considerable proportion of premature deaths in European cities could be avoided by lowering air pollution concentrations, particularly below WHO guidelines. The EU directive sets the annual mean limits of ambient pollution at 25 µg/m³ for PM2·5 and 40 µg/m³ for NO2, whereas the WHO recommendations are set at 10 µg/m³ for PM2·5 and 40 µg/m³ for NO2. Madrid has the highest NO2 mortality and Brescia in Italy has the highest PM2.5 mortality, while Scandinavian countries had the lowest mortality due to air pollution. 
Premature mortality due to air pollution in European cities: a health impact assessment, The Lancet, January 2021.