Clean Air Zones: what you need to know

The roll-out of Ultra Low Emission Zones (ULEZs), Clean Air Zones (CAZs) and other pollution-reducing schemes in cities across the UK is accelerating in 2021.

Following the implementation of the UK’s first ULEZ in London in April 2019, similar initiatives will be established in other major cities across England and Scotland.

The cities that have confirmed or expected CAZs are:

Bath – 15 March 2021

Birmingham – 1 June 2021

Leicester (expected) – Summer 2021

Oxford (expected) – August 2021

Bradford (expected) – October 2021

London – 25 October 2021

Bristol (expected) – 29 October 2021

Portsmouth – November 2021

Manchester – Spring 2022

Glasgow – Between February and May 2022

Edinburgh – Between February and May 2022

Dundee – Between February and May 2022

Aberdeen – Between February and May 2022

The cities that are planning CAZs are:

Newcastle – 2021

Sheffield – 2021


The basic premise of CAZs is similar to that of congestion zones. An area is marked out within a city, usually focused on the city centre. Vehicles travelling within this zone and judged to be excessively polluting face charges, depending on the size of the vehicle.

Larger vehicles like HGVs, coaches and buses that do not meet emissions requirements (explained in more detail below) are charged around £100, although this varies between cities. Private hire cars, taxis and regular passenger vehicles that are non-compliant can expect to pay less, but still incur a charge of around £10 a day.

Like London’s already existing ULEZ, the CAZs will be distinguished by signs to make motorists aware that they are entering the zone. They will also be ring-fenced by numberplate recognition cameras. These make a note of every vehicle that passes through the zone and checks them against a database to determine the charge.

The CAZs will, mostly, be in effect 24 hours a day, seven days a week. No reprieve is granted for bank holidays.


Since the goal of CAZs is to reduce emissions and improve air quality, zero-emissions vehicles have nothing to fear. However, drivers of vehicles that are not zero-emissions may be liable for charges. Two factors determine whether you will face a charge and at what level: (1) how many emissions your vehicle produces; and (2) what type is it, since, depending on the CAZ class, certain types of vehicles are exempt.

The general rule is that to travel within a CAZ without a charge, your vehicle has to be at least a Euro 4 emission standard compliant petrol model – in other words, registered after January 2006 – or, if it is a diesel, compliant with Euro 6 standards (registered after September 2015). If your vehicle meets these standards, in all probability you will not have to pay a charge.

However, even if your vehicle does fall outside of Euro 4 or 6, you may still be able to avoid a charge, depending on what kind of vehicle it is and the type of CAZ that you wish to drive through. Four types of CAZ exist, each of which targets different classes of vehicles. These are:



Newcastle was originally set to launch a CAZ in January 2021. However, the plan has been pushed back, due to a combination of the government being “ill-prepared” (according to Newcastle Council cabinet member Arlene Ainsley) and the fallout from an ongoing legal challenge by a company that lost its bid to provide numberplate recognition cameras to police the zone. Nevertheless, it is almost certain that Newcastle will gain a CAZ, although the precise date is uncertain. Focused on the city centre, it is currently set to be Class C, so skipping regular passenger cars. Assuming the January 2021 rates remain constant, which seems likely, HGVs, buses and coaches will be charged £50 to enter Newcastle’s city centre. Taxis and vans will pay £12.50.


Zone type: Class C

Cost per day for HGVs, buses and coaches: £50 (est)

Cost per day for taxis: £10, vans and lorries also £10 (est) 

Cost per day for regular passenger cars: £0

The prospect for Sheffield’s CAZ is less certain than Newcastle’s. Originally, a CAZ was set to be introduced later this year, but the effect of the coronavirus pandemic on air pollution – this has fallen up to 33% from 2019 levels – has caused city councillors to reconsider. The zone, as it is currently proposed, will be Class C, overlooking regular passenger traffic but penalising polluting HGVs, coaches and taxis. It is pencilled to cover Sheffield’s inner ring road and city centre, including Park Square. Under the current proposals, fees for the zone would have been in line with those for cities such as Newcastle, with non-compliant HGVs and buses charged £50 for entry, falling to £10 for taxis, vans and lorries.


Leeds and Liverpool were scheduled to receive CAZs. However, both cities have put plans on hold due to the coronavirus pandemic. In Leeds, this is likely to be  indefinitely since air quality has been judged to be regularly below the level that would legally require a CAZ. Nottingham has also cancelled its plans for a CAZ, instead opting to reduce air pollution by refitting buses and converting council-owned vehicles to hybrid or electric powertrains. In Cambridge, discussions to introduce a CAZ are ongoing but a decision has not been reached either way.