Speed restrictions to come into force to improve air quality and save lives in Wales

The measures are aimed at reducing levels of nitrogen dioxide where emissions have been found to exceed legal limits.

Poor air quality contributes to an estimated 2,000 deaths per year in Wales, with exposure affecting vulnerable population groups in particular. Gases such as nitrogen dioxide can increase the symptoms of people with lung diseases, while short-term exposure is associated with increased cardiovascular and respiratory morbidity.

The temporary 50 mph speed limits will be introduced at short stretches of road, between 1.4km to 5.9km in length, at the following five locations:

• A494 at Deeside
• A483 at Wrexham
• M4 between Junctions 41 & 42 (Port Talbot)
• M4 between junctions 25 & 26 (Newport)
• A470 between Upper Boat & Pontypridd

Other measures include increased signage to promote smooth traffic flow. The measures are expected to deliver immediate improvements to air quality, with emissions estimated to potentially reduce by up to 18% at the five locations.

Evidence shows that nitrogen dioxide emissions are at their lowest when light vehicles, the main contributors to emissions, travel at speeds between 40 and 50 mph. The speed limits are also expected to have a smoothing effect, with vehicles travelling at more constant speeds.  

The temporary speed restrictions are part of a range of actions being introduced by the Welsh Government to improve air quality in Wales, including a new £20m Air Quality Fund, a Clean Air Zone Framework and a new Air Quality website providing local data on air pollution levels.

Minister for Environment Hannah Blythyn said:

“I am committed to taking action to reduce air pollution in Wales to support a healthier future for our communities and protect our natural environment. Current levels of nitrogen dioxide exceed the legal limit at the five road locations, so we need to act as soon as possible.

“We have been carrying out investigations into all potential measures for reducing nitrogen dioxide levels. Our initial studies tell us that 50 mph speed limits should have the greatest potential to improve air quality at each location. The actions we take to improve air quality in Wales have a key role in supporting the right conditions for better health and well-being.”

Cabinet Secretary for Economy and Transport, Ken Skates, said:

“I want to see concrete measures put in place by the UK Government which focus on removing the source of the problem.  They have prevented us from taking our preferred course of action – it is now time for them to step up and use the powers which they have so closely guarded for the benefit of the people of Wales.”

“The root cause is the emissions from vehicles, but legislative competence for vehicle standards and fiscal measures, such as the Vehicle Excise Duty and Company Car Tax, remain with the UK Government. Despite repeated calls, the UK Government has consistently refused to devolve powers which allow us to improve standards and incentivise improved emissions through the tax regime.”  

A consultation is open until 19 June on plans to reduce concentrations of nitrogen dioxide, as part of the wider UK plan to tackle roadside NO2 concentrations.