1. London: Ultra Low Emission Zone (ULEZ):

   • London has one of the most well-known low emission zones, known as the Ultra Low Emission Zone (ULEZ).
   • ULEZ covers a central area of London, and vehicles entering this zone need to meet strict emission standards or pay a daily charge.
   • The ULEZ standards typically require vehicles to meet Euro 6 for diesel engines and Euro 4 for petrol engines.

2. Other UK Cities: Clean Air Zones (CAZ):

   • Several other cities in the UK have implemented or are planning Clean Air Zones (CAZ) to tackle air pollution.
   • Birmingham, Manchester, and other cities have introduced CAZ with charges for non-compliant vehicles.
   • The specific emission standards and charges vary by city.

3. Emission Standards:

   • The emission standards for vehicles are typically based on the Euro standards for air quality. For example, Euro 6 for diesel vehicles and Euro 4 for petrol vehicles are common requirements.

4. Penalties:

   • Non-compliant vehicles entering low emission zones may face penalties, including fines.
   • It's crucial for vehicle owners to check their vehicle's emission standard and compliance with the specific requirements of each low emission zone.

5. Check Local Authorities:

   • Local authorities in different cities are responsible for implementing and enforcing low emission zones. It's important to check with the relevant local authority for the most up-to-date information.

6. Exemptions and Discounts:

   • Some low emission zones provide exemptions or discounts for certain types of vehicles, such as electric or hybrid vehicles.
   • Businesses may also have options for support or exemptions.

7. Updates and Changes:

   • Low emission zone policies may change over time. It's crucial to stay informed about any updates or changes to the regulations in the specific cities you plan to visit.

For the latest and most accurate information, especially considering potential changes after my last update in January 2022, it's recommended to check the official websites of the relevant local authorities or the UK government's website.