Policy paper

Clean air zone framework

Updated 6 October 2022

This was published under the 2016 to 2019 May Conservative government

1. Introduction

1) We know that air pollution is the biggest environmental risk to human health, and we have a clear ambition and policy agenda to improve air quality backed up by significant investment. In 2019, Defra published the Clean Air Strategy, which the World Health Organisation welcomed as “an example for the rest of the world to follow”. This sits alongside the UK Plan for tackling roadside nitrogen dioxide concentrations (‘The NO2 plan’) published in 2017. Our landmark Environment Act 2021 helps to deliver key aspects of our Strategy.

2) The Act strengthens the Local Air Quality Management framework by placing greater emphasis on Air Quality Action Plans (AQAPs) setting out how air quality standards and objectives are to be achieved. We are also broadening the range of partners required to collaborate with local authorities in developing AQAPs. These partners will be required to identify additional actions they will take to help local authorities achieve air quality standards and objectives.

3) Clean air zones are one measure for helping us to deliver this ambition. This framework sets out the principles for the operation of clean air zones in England. It provides the expected approach to be taken by local authorities when implementing and operating a clean air zone under the NO2 plan.

What is a clean air zone?

4) A clean air zone defines an area where targeted action is taken to improve air quality and resources are prioritised and coordinated in order to shape the urban environment in a way that delivers improved health benefits and supports economic growth.

5) Clean air zones have been introduced with a specific focus on tackling NO2 concentrations in areas that are breaching legal limits. The UK are compliant with other limit levels of other exhaust pollutants, but clean air zones will also help to reduce public exposure to pollutants such as particulate matter. Previous versions of this document have referred to a ‘non-charging’ clean air zone where targeted measures can be put in place to tackle air pollution. A local authority could still choose to implement such a non-charging zone, and the measures and approaches described in Annex B could be considered in such a case. However, for the avoidance of confusion, for the purpose of this document, a clean air zone refers specifically to a charging clean air zone. This is an area where a local authority applies charges using powers under the Transport Act to deliver NO2 reductions. The previous version of this document referred to non-charging clean air zones along with a number of activities local authorities could take in such zones. As the term clean air zone has since come to refer specifically to a charging scheme version 3.0 of this document has removed the concept of a non charging clean air zone. Other measures local authorities can take, whether as part of/alongside a clean air zone; developed as a result of a local NO2 plan; or independently of a clean air zone are described in Annex B.

6) The NO2 Plan explains that “It is for local authorities to develop innovative local plans that will achieve statutory NO2 limit values within the shortest possible time…the UK government has identified clean air zones that include charging as the measure it is able to model nationally which will achieve statutory NO2 limit values in towns and cities in the shortest possible time. Given the potential impacts on individuals and businesses, when considering between equally effective alternatives to deliver compliance, the UK government believes that if a local authority can identify measures other than charging zones that are at least as effective at reducing NO2, those measures should be preferred as long as the local authority can demonstrate that this will deliver compliance as quickly as a charging clean air zone.

What is this framework?

7) This framework sets out the principles for the operation of clean air zones in England. It provides the expected approach to be taken by local authorities when implementing and operating a clean air zone (CAZ).

8) The primary audience for this document is those local authorities identified in the 2017 NO2 plan and supplement, and which have identified a clean air zone the preferred option to deliver compliance with legal limits for NO2. These authorities are required to follow this framework in designing and implementing their clean air zone, alongside other guidance provided by government.

9) If other local authorities want to consider implementing a clean air zone independently they are encouraged to refer to this guide. All clean air zones need to provide businesses and individuals with clear signals on what needs to change to improve air quality, while offering them a range of choices on the action they could take in response, for example about the vehicles they buy and how they use them, knowing they will be acceptable in all zones.

2. Access restrictions for clean air zones – operational standards and requirements

10) It is expected that any local authority putting in place a clean air zone, identified in a local plan developed as part of the NO2 plan, will follow these requirements.

Preparing and planning for a charging zone

11) Decisions about whether to introduce a charge based clean air zone will need to take account of a wide range of issues both in the zone and in neighbouring areas. These will include the:

• reduction in emissions and concentrations of NO2, and other pollutants required
• type of emission sources that need to be addressed
• type of vehicles that need to be addressed
• scope and boundary of the zone
• implications from any traffic displaced to surrounding areas
• social, economic and health benefits from the introduction of a zone

12) The introduction of the zone will need extensive engagement and consultation with neighbouring authorities, local communities and businesses to: explain the aims, including the potential health and economic benefits; understand any concerns; and assess the need for any mitigating actions.

13) In developing a zone, it is important to recognise that the longer businesses and individuals have to make these changes, the easier it will be for them to do so, and therefore the more likely they will. However, this needs to be balanced by the ongoing health impacts of pollution. Time will need to be allowed between formally announcing the details of a zone and the beginning of its operation to allow businesses and individuals to adjust.

The legal basis for introducing a clean air zone

14) The ability for charging authorities to introduce a clean air zone is set out in the Transport Act 2000. Part III of the Act empowers local authorities (as “charging authorities”) to make a local charging scheme in respect of the use or keeping of motor vehicles on roads.

15) The Clean Air Zones Central Services (fees) (England) Regulations 2020 enable the Secretary of State to charge local authorities in England for using the Clean Air Zones Central Services. The regulations describe how the central service offered to LAs as part of the NO2 plan operates. The government will consider whether to make this service available on a wider commercial basis in future.

16) Matters to be dealt with in charging schemes by charging authorities include:

• designating the roads and classes of vehicles subject to a charge
• the charges imposed
• the manner in which charges are to be made, collected, recorded and paid
• the period for which a scheme is in force
• exemptions and reduced rates from charges
• enforcement regimes and penalties for non-payment of charges

Classes of clean air zone

17) Central to the introduction of a clean air zone is consistency in the type of vehicles that will be allowed free entry. The class of clean air zone chosen should be sufficient to enable the zone to meet clear and ambitious air quality aims that will deliver associated health benefits.

18) In general vehicles, such as lorries and buses, or high frequency users such as taxis and private hire vehicles (PHVs) emit higher levels of pollution within the zone on a per vehicle basis. Clean air zones have been grouped into classes covering different vehicle types as set out in Annex A. The types of vehicles covered by a zone broaden from class to class.

19) When setting up a clean air zone, local authorities will need to consider the sources of vehicle pollution. They should consider each class of zone in order and select the most appropriate one to meet the air quality challenge in the zone.

20) Before introducing a Class A zone a local authority should explore all possible routes to reduce emissions from buses, taxis and PHVs through existing non charging routes, for example using licensing or working with bus operators through any of the new mechanisms in the Bus Services Act 2017 to raise the emission standards of vehicles entering the area.

21) To ensure a consistent approach on vehicles which frequently operate within the zone, taxis and private hire vehicles (PHVs) will be treated on an equivalent basis. Any local authority zone bringing in charging or licensing requirements for non-compliant taxis should also place similar requirements on non-compliant PHVs.

22) For a given class of zone all vehicle types identified as in that class should be subject to the restrictions, allowing for any agreed local exemptions. A local authority should not select individual vehicle types within a class, or ‘mix and match’ vehicles across classes (for example a zone could not charge only coaches and large goods vehicles (LGVs) – a zone covering all vehicles up to LGVs would have to be introduced).

Vehicle standards for entering or operating within a clean air zone

23) To ensure that only the cleanest vehicles are encouraged to enter or operate in a clean air zone, common standards need to be set for their entry. Vehicles that conform to more recent Euro standards should emit less pollution than older vehicles in their class. Annex A sets the minimum Euro standard for vehicles of that type which will be allowed free entry into the zone. Other vehicles should be subject to a charge unless they are covered by an exemption, a discount on the charge, or other acceptable vehicle requirements set out in this framework, such as meeting retrofitting or ultra low emission requirements. Successive emissions standards have been set by the European Commission for certain types of vehicle. There are separate standards for light vehicles (cars and vans) and heavy vehicles (heavy goods vehicles (HGVs), buses etc.). The standards for light vehicles are indicated with a number for example Euro 6, while those for heavy vehicles are indicated with a roman numeral for example Euro VI. The most recent standards are Euro 6 for light-duty vehicles and Euro VI for heavy-duty vehicles. See: Regulation (EC) No 715/2007 of the European Parliament and of the council and Air pollutant emissions standards.

2.5 Ultra low and zero emission vehicles

24) Fully electric or hydrogen fuel cell vehicles will not be charged for entering or moving through a clean air zone.

25) Other vehicles which meet the definition of ultra low emission vehicles and minimum emissions requirements set out in Annex A may apply for an exemption from the charge. These could include:

• hybrid vehicles that otherwise to do not meet the euro standard/age requirements for their type; and
• plug-in hybrid vehicles which are geo-fenced to operate in electric only mode within the zone.

2.6 Retrofitted vehicles and accreditation

26) Retrofitting a vehicle can provide an alternative to buying a new vehicle to meet the standards for a clean air zone. There are a range of existing and emerging retrofitting options for vehicles and it can be difficult for purchasers and local authorities to know whether a particular technology is credible.

27) The government has developed the Clean Vehicle Retrofit Accreditation Scheme (CVRAS) to provide independent evidence that a vehicle retrofit technology will deliver the expected pollutant emissions reductions and air quality benefits. The scheme enables drivers, technology manufacturers, businesses and local authorities to be confident that the retrofit technologies being used provide the appropriate emissions reductions for free entry to a clean air zone. Retrofitted vehicles which meet the requirements of a clean air zone as accredited under this scheme will be exempt from a charge.

2.7 Future standards

28) The UK will end the sale of new petrol and diesel cars and vans by 2030 and, from 2035, all new cars and vans must be zero emissions at the tailpipe. This means over the next few decades the number of electric and ultra low emission vehicles on UK roads will significantly increase. It is one of the aims of clean air zones to support this transition and they will always favour those vehicles with the very best environmental performance.

29) Historically vehicle standards have evolved over time to take account of both technological advances and changes in the evidence on things like the impact of emissions. The ambitions of cities will likewise increase.

30) To meet these needs the minimum vehicle standards in Annex A of this framework may be periodically updated. This progression of standards should be considered in setting the ambition for clean air zones and driving the early adoption of the best technologies. However, it is recognised that businesses and others need sufficient certainty in order to plan and make the most economic decisions in response to clean air zones, therefore:

• it is intended that the current standards set out above will remain in place until at least 2025, and for cars and vans, Ultra Low Emission Vehicles (ULEVs) and Zero Emission Vehicle (ZEVs) will always be the most favourable category.

31) It is recognised that data and understanding on emissions from vehicles will continue to evolve. Should significant new evidence on emissions emerge that may necessitate the consideration of an earlier revision than set out in this framework, the government will ensure a sufficient time period before any changes are introduced.

2.8 Vehicle detection – automatic number plate recognition

32) Automatic number plate recognition (ANPR) will be used for the operation of clean air zones. Cameras will capture all vehicles on the monitored road(s), regardless of whether it is their final destination, or they are moving within or passing through the zone.

33) The number and distribution of fixed and/or mobile cameras required will be determined by the relevant local authority in order to deliver the objectives of their clean air zone.

34) The Joint Air Quality Unit has worked with the Driver Vehicle and Licensing Agency and others on identifying compliant vehicles with the clean air zone standards set out in this framework. Drive in a clean air zone guidance is available for vehicle owners to check the status of their vehicles.

Hours of operation

35) It is open to any local authority to decide on the hours when a scheme operates. If the local authority chooses to implement a clean air zone, the government has assumed in its modelling that the zone would operate 24 hours a day, every day of the year. However, if a local authority can demonstrate that, by operating on a reduced hours basis, it will still achieve compliance with air quality limit values in the shortest possible time, it could bring forward such a scheme.

Signing

36) A minimum requirement for setting up a clean air zone is to have signs in place along major access routes to clearly delineate the zone. Government has developed signs and will provide guidance to local authorities implementing clean air zones to ensure these are implemented appropriately and consistently.

Exemptions and discounts

37) There is a general presumption that the requirements for clean air zones will apply to all vehicles according to the relevant zone class.

38) There will be certain circumstances where exemptions and discounts from a charge will be appropriate. This may be because of: a person’s particular circumstances; the type of vehicle concerned may be difficult or uneconomic to adapt to comply with a zone’s requirements; or the operation a vehicle is engaged in is particularly unique or novel.

39) Discounts and exemptions should, in general, be based on the principal that:

• specialist vehicles that can never be compliant should qualify for an exemption from a charge
• a sunset period should be allowed for specialist or more novel vehicles that can become compliant in a suitable time to allow for them to be changed

40) While exemptions should be kept to the minimum necessary in order to maximise the benefits of a zone, local authorities may also consider additional exemptions or discounts based on particular local circumstances. Local authorities may consider ways in which the cost of any charge to enter areas could be reduced for groups they identify as facing particular challenges, so long as this is achieved in a way which does not slow down the achievement of the outcomes of the zone. This might, for example, take into account the location of a charging zone in relation to key local businesses or services.

41) Local authorities will also need to think about enforcement relating to exemptions and discounts in designing a zone. This section sets out where national exemptions should apply, and the circumstances in which local exemptions or discounts may be appropriate. Additional exemptions should not be applied where doing so would negate the overall benefits of the zone.

Historic and specialist vehicles

42) A small number of vehicles will be exempt from paying a charge to enter a clean air zone due to their age and/or their unsuitability for retrofitting or purchasing a replacement vehicle. This will include:

• vehicles with a ‘historic’ vehicle tax class
• certain types of non-road going vehicles which are allowed to drive on the highway such as agricultural machines; digging machines; and mobile cranes

43) Local authorities should assess the nature of the specialist vehicle(s) concerned and provide for an exemption on a case by case, or type by type basis.

44) Military vehicles are exempt from charges by virtue of Section 349 of the Armed Forces Act 2006.

Emergency service vehicles

45) A local authority should liaise closely with the emergency services to understand the type of vehicles in their fleets and the activities for which they are used.

46) Emergency services use a range of specialist and/or novel or adapted vehicles, such as aerial ladders and major incident command vehicles where it may generally not be suitable to provide a replacement vehicle to the standards of the zone. These vehicles will be exempt from a charge.

47) Local authorities may exempt emergency service fleets more generally should they choose to do so. Local authorities are encouraged to reach voluntary agreements with the emergency services over the use of vehicles in their fleet within clean air zones. The agreements should be as ambitious as possible, including seeking to agree to use vehicles in line with the standards in this framework as far as practicable, particularly in the case of non-emergency work.

Blue Badge holders and vehicles used by a disabled person exempt from Vehicle Excise Duty

48) Vehicles within the disabled passenger vehicle tax class will be exempt from paying a charge in a clean air zone.

49) A local authority may choose to give a discount or exemption to holders of a Blue Badge whether driving a vehicle, or as a passenger, should analysis of local circumstances warrant such an approach.

Community transport vehicles

50) Community transport, such as minibuses, provided by small operators and local groups can give an important access to employment, education and training for people who may otherwise be isolated. Local authorities may choose whether to give a discount or exemption to such services based on their assessment of local circumstances.

Residents who live within a clean air zone

51) It is important that local authorities consider the impact of a zone on local residents. By the simple virtue of their location they will not have the choice open to others of avoiding a zone when in a vehicle.

52) Local authorities can consider allowing residents who live within a clean air zone additional time to comply with vehicle restriction requirements by providing for a discount on charges where these are included. Discounts may be set at a local authority’s discretion at up to 100% of a charge.

53) In assessing the need for a grace period, and the length of time one may be necessary for, local authorities should take account of the change needed in vehicle mix to meet a zone’s air quality aims, as well as the social, economic and health impacts of a zone’s introduction.

54) Should a local authority decide to give residents who live in a clean air zone additional time to comply, they may wish to consider a sunset period from a zone’s introduction during which the discount would apply. Local authorities should ensure discounts are only available while residents live within a zone.

55) While residents within a charging clean air zone will be directly affected, it is also important that the impact on residents in neighbouring areas are considered. A local authority may also consider whether a discount for residents in designated areas next to the zone should be provided in line with the requirements set out in this section. Care will need to be taken that this does not undermine the aims of a zone, and these types of discount are expected to be kept to a minimum.

Levels of charge

56) Local authorities should set the level of charge for vehicles entering a zone appropriate to their local circumstances. They should consider the behaviour change needed to deliver the ambitions for the zone; the local economic and social factors of the zone and surrounding areas; and the operational costs of running a scheme. Local authorities should not set the level of charge as a revenue raising measure. The Transport Act 2000 requires any excess revenue that may arise from charges above the costs of operation to be re-invested to facilitate the achievement of local transport policies and these should aim to improve air quality and support the delivery of the ambitions of the zone, while ensuring this does not displace existing funding. Such charges may not be used as a form of taxation to raise revenue generally.

57) Local authorities will be able to impose penalty charges for the non-payment of clean air zone charges. They will be able to provide discounts on these penalties for prompt payment and there will be a fair procedure for making an appeal. Local authorities should publicise the levels of entry charge and penalty as part of their communications activity related to the introduction of a zone. The signing of the zone should be clear to ensure that drivers are not penalised for unintentionally entering a charging zone, and that it is clear how drivers can avoid entering the zone.