Clean air schemes are go

01 June 2021 | David Young

There are now a number of confirmed and proposed clean air schemes in UK towns and cities aimed at reducing harmful emissions from road transport which contribute to poor air quality

Clean air schemes are go

The majority of these schemes are Clean Air Zones (CAZs) which have restrictions on the type and age of vehicles that are allowed to enter them. Drivers of vehicles allowed to enter CAZs may or may not have to pay a charge to do so.

There is a government vehicle checker to help people determine whether they can drive into CAZs. More locations are being added to the checker as further details about confirmed CAZs emerge.

London operates an Ultra-Low Emission Zone (ULEZ) which is similar to a CAZ. Transport for London provides its own vehicle checker for drivers wanting to enter the ULEZ. The principles for setting up a CAZ in England are outlined in the Clean Air Zone Framework published by DEFRA and the DfT.

Clean air schemes



Clean Air Zone


Zero Emission Zone*


Ultra-Low Emission Zone*


Low Emission Zone*


*Restrictions may vary between various ZEZs, ULEZs and LEZs. There is no prescriptive framework as there is with CAZs.

Classes of CAZ


type of vehicle affected by restrictions


Buses, coaches, taxis, private hire vehicles


Class A + HGVs


Class A + Class B + large vans, minibuses, small vans


Class A + Class B + Class C + cars, motorcycles, mopeds

Minimum Euro emission standards for vehicles to gain entry to a CAZ

Vehicle type

Emission standard

Buses and coaches

Euro VI


Euro VI


Euro 6 (diesel) or Euro 4 (petrol)


Euro 6 (diesel) or Euro 4 (petrol)

Motorcycles and mopeds

Euro 3