The UK has challenging legal obligations in relation to NO2 limits and is required to achieve compliance in the shortest possible time.
The government has identified a number of local authorities to develop local air quality plans to bring forward compliance dates within the shortest possible time. This can involve establishing charging clean air zones (CAZ). In some cases, HGVs classed as Euro V or below will incur a charge for entering a CAZ. The CAZ framework vehicle emissions standards are the same across CAZ, London ULEZ or LEZs in Scotland however which vehicles are in scope is at the discretion of the local authority.
Energy Saving Trust in partnership with Zemo runs the Clean Vehicle Retrofit Accreditation Scheme (CVRAS) which is a robust certification scheme for manufacturers to seek accreditation for any retrofit technologies that can bring a pre-Euro VI HDV up to Euro VI equivalent emission standards and provide lower-cost options for achieving clean air zone compliance. Further information is available here.
Only retrofit systems that are CVRAS approved will be recognised by local authorities implementing chargeable CAZs.
Set up in 2008, the London LEZ applies to heavy duty vehicles and vans and covers the Greater London boundary. In March 2021, the Mayor of London introduced the new ULEZ standards for heavy duty vehicles (buses, coaches, HGVs and larger vehicles) for the LEZ and most diesel vehicles need to meet minimum Euro emission standards (Euro VI for HGVs) or pay a daily charge to travel.
The Mayor of London introduced the ULEZ in April 2019 which initially applied to the same area in central London as the Congestion Charging Zone. The ULEZ expanded out to a boundary set by the North and South Circular in October 2021 and extended further to the Greater London boundary (generally follows the M25) on 29 August 2023. The ULEZ applies to all vehicles so can be considered a Category D CAZ meaning all petrol vehicles need to be Euro 4/IV and all diesel vehicles need to be Euro 6/VI with motorcycles required to be the Euro 3 standard.
For more information on the London ULEZclick here click here.
Outside of London the chargeable CAZs that are currently implemented are in Bath, Birmingham, Portsmouth, Bradford, Bristol, Sheffield and Tyneside (Newcastle & Gateshead). The Manchester CAZ in currently under review.
CAZ Category
Vehicles charged
A
Buses, coaches, taxis and private hire vehicles
B
Buses, coaches, taxis, private hire vehicles and HGVs
C
Buses, coaches, taxis, private hire vehicles, HGVs, vans and minibuses
D
Buses, coaches, taxis, private hire vehicles, HGVs, vans, minibuses, cars and motorcycles
In Scotland there are four designated LEZs. The Glasgow LEZ came in to force on 1 June 2023 with
Edinburgh, Dundee and Aberdeen all planned to implemented over the coming years. All LEZs in Scotland will include all vehicle types (so equivalent to a CAZ D in England) however implementation dates and dates when charging will commence vary. Also a significant difference for LEZs in Scotland is that there is no ability to pay a charge to enter and penalty charge notices (PCNs) will be issued to operators of non-compliant vehicles that are found to have entered the zone. These charges will double on each entry to deter persistent offenders but capped at £480 for a car or van and £960 for a heavy-duty vehicle or minibus.
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