Skip advert
Advertisement

Welsh speed limits lowered to combat illegal emissions

Rising nitrogen dioxide levels prompt Welsh Government to reduce national speed limit on some roads to 50mph

Illegal levels of nitrogen dioxide pollution have prompted the Welsh Government to announce a speed limit reduction over five major stretches of road.

By lowering the speed limit to 50mph on two sections of the M4 motorway, as well as parts of the A494, the A483 and the A470, the Welsh Government hopes to bring about an 18 per cent reduction in harmful emissions.

Advertisement - Article continues below

Best green low-emissions cars of 2018

The new reductions are to come into force in the next two months, and are expected to bring about “immediate results”. One section of the M4 near Port Talbot is already subject to a 50mph speed limit, which is being extended as part of the plans.

Wales’ Minister for Environment, Hannah Blythyn, said: “I am delighted to announce a package of measures to improve air quality in Wales… 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.”

Responding to the new limits, Steve Gooding, director of the RAC Foundation said speed limits were being set with an inconsistent “patchwork” approach, adding: "Ironically there will be stretches of road where drivers actually struggle to reach anything like 50mph, and if there's one thing worse for air quality than vehicles hurtling along at high speed, it's where they sit nose to tail in jams."

Skip advert
Advertisement
Skip advert
Advertisement - Article continues below

Edmund King, president of the AA, called for intelligent management of speed limits, saying: "If speed limits are to be reduced on parts of the M4 in Wales it should be a flexible system that varies speeds and is linked to air quality monitoring, so the speed limits are only reduced when air quality levels are exceeded."

Sections of road with planned speed limit reductions:

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

Opinion: emissions-based speed limits

By Hugo Griffitths

"The big question is whether this Welsh plan sets a precedent for future emissions-based speed limits - particularly as the preponderance of smart motorways means this could be achieved at the flick of a switch when air quality levels fall. But with sustained unease over diesel emissions motorists must feel, once again, as if they are being held responsible for the mistakes of Government and business. There is a glimmer of hope, though: a recent breakthrough in the management of diesel emissions means punitive and restrictive measures to tackle pollution could soon be a thing of the past."

Will you be affected by the Welsh Government’s decision to reduce speed limits on certain roads? Tell us what you think in the comments section below…

Skip advert
Advertisement
Skip advert
Advertisement

Most Popular

New Audi Q4 e-tron facelift: electric SUV gets updated look and jump in range
Audi Q4 e-tron facelift - front action

New Audi Q4 e-tron facelift: electric SUV gets updated look and jump in range

The hugely popular Audi Q4 e-tron looks to back up its success with a timely update
News
27 Apr 2026
New Omoda 2 set to steal the Ford Puma’s thunder with £20k price tag
Omoda badge

New Omoda 2 set to steal the Ford Puma’s thunder with £20k price tag

One of the UK’s fastest-growing brands is aiming for the B-segment and its huge sales volumes
News
27 Apr 2026
New Zeekr 8X review: 1,381bhp plug-in hybrid SUV is an absolute tech-fest
New Zeekr 8X plug-in hybrid - front tracking

New Zeekr 8X review: 1,381bhp plug-in hybrid SUV is an absolute tech-fest

While the Zeekr 8X comes with huge levels of power, space and tech, it can't quite match its European rivals when it comes to its driving experience.
Road tests
25 Apr 2026

Find a car with the experts