Hard Times: Improving Air Quality with Clean Air Zones

Read more articles by: Rob Hann,

In Hard Times, Charles Dickens – rarely considered an environmentalist – described Victorian London as an “ugly Citadel, where Nature was as strongly bricked out as killing airs and gases were bricked in[1]”.  Even before the invention of cars, noxious emissions in Victorian London were up to fifty times higher than in the decade after the clean air acts. Pollution,  Dickens reminds us, has been ‘bricked in’ to urban life since the industrial revolution: threatening the health, longevity, and wellbeing of anyone who has lived in a city since the mid-19th century.  But what can we do to mitigate this age-old problem?

Clean Air Zones: Coming to a Town Near you

Following the latest decision in the ClientEarth Litigation [2] – which acknowledged the Government’s duty to mitigate the “real and persistent risk of significant harm” presented by the UK’s air quality – local and central government policymakers have been urgently implementing innovative solutions to improve the air quality in major cities. One such solution has been Clean Air Zones (“CAZ”).  CAZ are defined areas in which targeted action is taken to improve the quality of air by reducing emissions caused by traffic congestion and exhaust fumes. In many instances, CAZ will be roads or defined areas in which certain vehicles will be charged or fined for entering.  In recent years, the number of CAZ has been rapidly proliferating across the country with existing areas being extended as local authorities seek to deliver the changes promised in their Climate Emergency declarations.

As demonstrated by a useful map published by the RAC, a plethora of UK cities have been considering introducing CAZ with dozens of schemes pending approval. On 25 October 2021, London’s Ultra-Low Emissions Zone was extended to be 18 times its original size and will now capture some of the city’s most populous – and residential – areas such as parts of Brent, Barnet and Newham. Outside the capital, CAZ have already been confirmed in  .  Whilst this is likely to be welcomed by environmentalists and public health officials, local opposition to those schemes which involve charging is often high. Those drivers who are simply passing through an unfamiliar City or Town to (perhaps) take teenage off-spring to visit various University options, may also find themselves wondering ‘what the Dickens is going on?’ as signs appear announcing the introduction of new charging CAZ.

A Tax on Drivers?

Viewed by some as a tax on sole traders and small businesses, charging in a CAZ typically falls under four Classes – Class A, B, C and D. Which vehicle is affected depends upon which CAZ the local transport authority has decided to adopt in the area.  The different classes of vehicle covered under the 4 Classes are as follows:

  • Class A – covers buses, coaches and taxis.
  • Class B – affects buses, coaches, taxis, private hire vehicles and heavy goods vehicles.
  • Class C – covers buses, coaches, taxis, private hire vehicles, heavy goods vehicles, vans and minibuses.
  • Class D – is all-encompassing and includes buses, coaches, taxis, private hire vehicles, heavy goods vehicles, vans, minibuses and domestic cars, plus the local authority has the option to include motorcycles.

By charging, policymakers have sought to incentivise the adoption of Electric Vehicle (EV) technology particularly amongst commercial vehicles (though Class C and D may capture some domestic vehicles) and thus reduce emissions across local supply chains and transport networks. To many, this will seem like a logical way to incentivise the transition to EV; however, when the same tiers of changes are applied to residents in London, valid concerns regarding the equity (or otherwise) of taxing the less well-off owners of old cars are likely to be expressed.

In a similar vein, some local authorities fear that a charging CAZ may deter visitors, tourists and businesses to their regions at a time when Councils are seeking to entice people back into city centres to help rebuild local economies in the wake of the Covid 19 pandemic. However, given our understanding of the effects of air pollution on human health (including evidence linking it to Covid-19 hospitalisations) the public health and environmental imperative to improve air quality makes the case for action compelling.


This week, the focus of world leaders at Glasgow’s COP26 will be fixed on ‘Net Zero’ – the goal of reducing Green House Gas emissions to a level equal to quantities being removed from the atmosphere.  Great Expectations have been raised in advance of COP26. The hope is that the summit will lead to a major push by World Leaders to clean up the air we breathe; to dramatically reduce harmful carbon emissions and, in the process, to ease the impact on the climate and the environment. However, it is clear that some of these necessary changes to our existing way of life, and some of the impact from measures designed to improve the quality of the very air we all breathe have already arrived.

Given the widespread adoption of CAZ which looks set to take hold across large areas of England in the next few years, driving around the Country will involve more than a quick glance at the satnav to check out the route. Motorists will also need to explore whether they are driving a vehicle which may trigger a charge through an area covered by a charging CAZ.

Perhaps that’s a small price to pay for what should be something we all take for granted – clean air to breathe?

[1] Charles Dickens, Hard Times.

[2] R (Client Earth (No 3)) v (1) Secretary of State for Environment, Food And Rural Affairs (2) The Secretary of State for Transport and (3) Welsh Ministers [2018] EWHC 315 (Admin)) 2018


This article is for general awareness only and does not constitute legal or professional advice. The law may have changed since this page was first published. If you would like further advice and assistance in relation to any issue raised in this article, please contact us by telephone or email enquiries@sharpepritchard.co.uk.

Posted in Energy, Latest news and blog, Local government, Rob Hann.