Low Emissions Zones and What It Means For Drivers

Low Emissions Zones are being introduced in major cities across the UK.

What are they and how will they affect drivers?

LEZ or CAZ - what are they and how do they work?

Low Emissions Zones (LEZs) and Clean Air Zones (CAZs) are often used interchangeably to describe inner-city areas where drivers of older, more polluting vehicles must pay to drive through.

The idea being to encourage drivers to use newer, less polluting vehicles or switch to public transport.

London has two zones designed to restrict the use of more polluting vehicles. The Ultra-Low Emissions Zone (ULEZ) covers an area up to the North and South Circular roads within the capital, and is set to expand to cover most areas within the M25 orbital motorway in August 2023.

The other is the Low Emission Zone, which covers most of greater London but only applies to HGVs, buses, and coaches, not private cars.

Other UK cities have also introduced their own clean air zones.

Birmingham’s CAZ became operational in 2021, covering all roads within the Middleway Ring Road. Bristol’s CAZ came into force on 28 November 2022.

Oxford’s Zero Emission Zone is very small, covering some or all of nine streets in the city centre, and all private cars other than electric ones must pay £2 to £10 to enter the zone.

Glasgow city centre was the first area in Scotland to have a low emission zone introduced in December 2018. Edinburgh is to follow suit sometime in 2024.

Why were LEZ and CAZ introduced?

Air pollution is a growing problem in cities and towns worldwide, with evidence indicating that exhaust fumes from older diesel cars are particularly harmful to human health.

Nitrogen oxides and particulate matter, such as microscopic pieces of soot, are linked to heart disease, asthma, and other respiratory illnesses. These emissions build up in the air, especially in dense urban areas, and are breathed in by people.

To tackle this problem, the authorities have introduced these clean air zones.

Diesel cars made since around 2016 must, by law, have diesel particulate filters that trap the tiny pieces of soot, and selective catalytic reduction (SCR), which is more commonly known as AdBlue.

This liquid is squirted into a diesel car’s exhaust gases, converting nitrogen oxides into water and nitrogen.

Diesel cars have to have SCR to meet - Euro 6 emission standards - which is the criteria for whether such a vehicle incurs a fee for entering a low-emission/clean-air zone.

Petrol cars emit more carbon dioxide than diesels, but little-to-no particulate matter and much less nitrogen oxide, hence earlier Euro 4 standards (introduced over 2005/6) are used as the barrier to entry for petrol cars driving into LEZ and CAZ.

How will LEZ and CAZ affect drivers?

If you have a newer, cleaner car that meets the Euro 6 or Euro 4 emission standards, then you should have no issues driving in LEZ and CAZ areas without incurring any fees.

However, if your vehicle does not meet these standards, then you will need to pay a fee to enter the zone.

Fees can vary depending on the location and type of vehicle, but they typically range from £8 to £100 per day.

For some drivers, the introduction of LEZ and CAZ may be an inconvenience, but for others, it is proving to be an incentive to switch to a cleaner, more environmentally friendly vehicle.

And with the recent push we’ve seen towards electric and hybrid vehicles, it's becoming easier and more affordable to make that change.

What about public transport?

One of the other key aims of LEZ and CAZ is to encourage the use of public transport. Which is seen by many as a cleaner and more environmentally-friendly way to travel. Again, the rise of all-electric buses is fuelling this assertion.

In some cases, public transport may be exempt from LEZ and CAZ fees, or may be subject to lower fees.

What else can drivers do?

If you're not currently not in the position of move to a cleaner vehicle, or able to make use of public transport, there are still some steps you can take to reduce your impact on the environment:

• Drive less. Perhaps not a popular option. But consider carpooling, walking, cycling, or combining trips in a bid to lower the amount of driving.
• Drive smarter. Avoid aggressive driving and, where possible and safe, use cruise control on the motorway.
• Choose cleaner fuels. If you own a diesel car, the use of high-quality diesel fuel that contains less sulphur helps to reduce emissions.
• Plan ahead. Before driving into an LEZ or CAZ, check whether your vehicle is compliant and be prepared to pay any fees that may apply.