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Ken Skates AM, Minister for Economy and Transport

First published:
7 October 2019
Last updated:

This was published under the 2016 to 2021 administration of the Welsh Government

On 24 June 2018, the Minister for Environment provided an Oral Statement to Assembly Members informing them of our plans to reduce air pollution in Wales to support a healthier future for our communities, our natural environment and our country.

Members were informed across Wales there are 5 locations on our motorway and trunk road network that exceed the legal limit for nitrogen dioxide (NO2) - A494 at Deeside; A483 near Wrexham; M4 between junctions 41 and 42, Port Talbot; M4 between junctions 25 and 26, Newport; and A470 between Upper Boat and Pontypridd.

Detailed investigations, including modelling using the approach set out in the Welsh Transport Appraisal Guidance (WelTAG), commenced in 2017 to establish the measures required to achieve compliance with The 2008 Ambient Air Quality Directive (2008/50/EC) and the corresponding Air Quality Standards (Wales) Regulations 2010, in an aim to achieve compliance as soon as possible, in a way which reduces human exposure as quickly as possible and where compliance with the limit values is not just possible but likely.

Initial investigations indicated 50 mph speed limits had the potential to achieve compliance in the shortest possible time, we acted immediately, implementing them at each of the 5 sites in June 2018 to improve public health. The final WelTAG report confirmed initial findings and 50 mph speed limits were identified as the measures most likely to achieve compliance in the shortest possible time in the Welsh Government’s Supplemental Plan to the UK Air Quality for Tackling Roadside Nitrogen Dioxide Concentrations, published in November 2018.

We have now published an interim report containing the results of 12 months of roadside monitoring of NO2 levels following the introduction of the speed limits on our website.

The data collected so far has shown a reduction in NO2 levels at all 5 locations. However, air quality remains a complicated issue and establishing cause and effect takes time. It is too early to say and make any firm conclusions on the effect the 50mph speed limit has had on the NO2 limits. Additional roadside data will be required before this improving air quality trend can be confirmed and a further report will be released in March 2020. 

I am aware speed compliance has been an issue over the past 12months and as a result, average speed cameras have been erected at four of the sites to monitor traffic speeds, whilst the M4 in Newport has spot cameras already place.

The reduction in NO2 indicated by the latest roadside monitoring is good news, however, we will not be complacent where public health is concerned. In line with the supplemental plan, we will continue to strive to achieve our goal of achieving air quality compliance in a way which reduces human exposure as quickly as possible and where compliance with the limit values is not just possible but likely. This includes the continued development and stakeholder engagement on the other measures namely, Precautionary Retained Measures.