The UK ministries for Environment, Food and Rural Affairs (Defra) and Transport (DfT) have published a joint air quality framework for Clean Air Zones which opens the door to emissions charging in English cities in addition to London.

In the policy paper, Air quality: clean air zone framework for England, the UK Government sets out the expected approach to be taken by local authorities when implementing and operating a zone to improve air quality. The aim is to reduce the impacts on people’s health of pollutants such as nitrogen dioxide (NO2) and particulates by taking action in urban areas with air quality problems.

The document says that though UK air quality has improved over recent decades thanks to concerted action at all levels, poor air quality remains the country's largest environmental risk to public health.

The framework explains the approach local authorities should take if they are introducing a Clean Air Zone, and the types of measures they should include, possibly including charging cars that do not meet emissions standards.

Clean Air Zones are areas where targeted action is taken to improve air quality. This can include restrictions to encourage only the cleanest vehicles to operate in the city if pollution problems are particularly persistent, as long as they are accompanied by other a range of other actions. However, there is no requirement to set up a charging zone.

Clean Air Zones are defined geographic areas used as a focus for a range of measures to improve air quality and fall into two categories, either with or without the need for additional charge-based access restrictions (Charging and Non-charging Clean Air Zones).

Charging Clean Air Zones would require vehicle owners to pay a charge to enter, or move within them if the vehicle did not meet the particulate standard for their vehicle type in that zone.

The framework has been welcomed by both environmental groups and the transport industry.

Philip Sellwood, Chief Executive of the Energy Saving Trust, said the Government’s air quality plan showed a commitment to improving air quality but that the final plan needed more detailed proposals with policies followed through. “The key thing is that this isn’t all about punitive measures for the so-called offenders,” he said. “If we are to successfully realise the benefits of clean air zones then both businesses and private drivers need advice and support to transition to ultra-low emission vehicles. We’ll be working in Leeds, Birmingham, Nottingham, Derby and Southampton to help make clean air zones a reality.”

Ben Kite, Managing Director of ecological consultancy, EPR, said: "This latest strategy rightly focuses on the level of traffic-related emissions in towns and cities, where air pollution poses the greatest public health risk. However, there is little sign that enough thought has been invested in determining how to ensure that pollution is not simply displaced to other areas not currently targeted for air quality management."

Kite believes the strategy could have sought to make better use of the land-use planning system  to tackle air pollution in a more holistic sense. "Much of the burden for delivering action is also placed onto individual local authorities, risking a disjointed and inconsistent approach," he continued, adding: "There is very little new guidance for planners and environmental practitioners as to how plans to reduce air quality impacts can be implemented in practice, on a local level.”

Mike Hawes from the Society of Motor Manufacturers and Traders (SMMT), also welcomed the draft proposals, pointing out that the proposals mean that the new Euro 6 diesels, which have been on sale for the past two years, will not face any penalty charges anywhere in the UK.

“We look forward to working with government to encourage the uptake of the latest, low emission vehicles, regardless of fuel type,” he said, adding: “The government is keen that local authorities avoid charging consumers and businesses for driving their vehicles if other more effective policies can be found. Industry is committed to improving air quality across our towns and cities and has spent billions developing new low emission cars, vans, trucks and buses and getting these new cleaner vehicles onto our roads quickly is part of the solution. We're encouraged that plans to improve traffic flow and congestion, as well as increase uptake of electric and hybrid vehicles, will be prioritised in towns and cities.

David Sanders of refrigerated transport technology company Dearman commented: “The Clean Air Zone framework rightly highlights the impact of transport refrigeration units (TFUs) on Britain’s air quality. These diesel-run units are disproportionately polluting and local authorities implementing clean air zones should encourage fleet operators to shift to the affordable zero emission units that are already available. The transport sector faces ever closer scrutiny because of its reliance on diesel, but the industry needs support as well as regulation if it is to transition to cleaner alternatives, that is why the draft air quality plan as a whole must encourage take-up of cleaner, greener technologies.”
According to Dearman, there are roughly 84,000 TRUs on Britain’s roads, many of which depend on outdated auxiliary diesel engines, which can emit up to six times as much nitrogen oxide (NOx) and almost 30 times as much particulate matter as a Euro 6 heavy goods vehicle engine.