The M4 in Wales has a limit of 70 mph (112 km/h) for cars, except for permanent 50 mph (80 km/h) limits at Newport, between junctions 24 and 28, and at Port Talbot, between junctions 41 and 42. Both are enforced by average speed cameras. The A55 in north Wales follows the normal national limits, with average speed cameras on the westbound climb at Rhuallt Hill.
| Road | Stretch | Limit and cameras |
|---|---|---|
| M4, Newport | Junctions 24 to 28 | 50 mph, average speed cameras both ways |
| M4, Port Talbot | Junctions 41 to 42 (cameras junctions 40 to 42) | 50 mph, average speed cameras both ways |
| A470, Pontypridd | Upper Boat to Pontypridd | 50 mph, average speed cameras both ways |
| A483, Wrexham | Junctions 5 to 6 | 50 mph, average speed cameras both ways |
| A494, Deeside | St David's Park to Deeside Industrial Park | 50 mph, average speed cameras both ways |
| A55, Rhuallt Hill | Westbound only | Average speed cameras, limit as signed |
| A5, Cerrigydrudion | Westbound only | Average speed cameras, limit as signed |
What is the speed limit on the M4 in Wales?
The speed limit on the M4 in Wales is 70 mph for cars and motorcycles, and 60 mph when towing a caravan or trailer, apart from the 50 mph stretches at Newport and Port Talbot. Most vans can also do 70 mph on the motorway, and lorries over 7.5 tonnes are limited to 60 mph. Temporary limits at roadworks can apply anywhere, so the sign in front of you always comes first.
Is the M4 at Newport 50 mph all the time?
Yes, the M4 at Newport is 50 mph all the time. The permanent limit runs for 13 km from junction 24 (Coldra) to junction 28 (Tredegar Park), and Traffic Wales says enforcement runs 24 hours a day, 7 days a week, allowing for vehicles joining and leaving between the junctions. A quiet road at 3am has the same limit as the morning rush.
Why is the M4 50 mph around the Brynglas tunnels?
The limit is there to smooth traffic flow, cut congestion and reduce collisions. It came from a recommendation in Lord Burns' report for the South East Wales Transport Commission. Traffic Wales says late lane changes and varying speeds often cause flow to break down near Newport, especially approaching the Brynglas tunnels. The earlier variable speed limit helped off-peak but did little at peak times, so average speed control replaced it. Enforcement began on 17 November 2022.
Is the M4 at Port Talbot 50 mph?
Yes, the M4 at Port Talbot has a 50 mph limit between junctions 41 and 42, brought in to reduce pollution. The Welsh Government's 2026 list gives the average speed cameras here as running from junction 40 (Tai Bach) to junction 42 (Earlswood), so keep your speed down for the whole stretch and follow the signs.
Where are the 50 mph zones in Wales?
Wales introduced 50 mph limits at five locations: the M4 at Newport and Port Talbot, the A470 near Pontypridd, the A483 at Wrexham and the A494 at Deeside. The table above gives the stretches. The Welsh Government describes them as the first environmental speed limits of their kind in the UK.
Why are there 50 mph limits in Wales?
The 50 mph limits exist to cut nitrogen dioxide pollution beside busy roads. The Welsh Government says it has a legal duty to meet pollutant limits, and that regular checks found levels above the legal limit at several points on its network. Research for light vehicles indicates emissions are lowest at speeds up to 50 mph, which is where the number comes from.
Why are some speed cameras green in Wales?
The cameras at these sites are green, rather than the standard yellow, to show that they are measuring speeds for air quality purposes. That is the Welsh Government's own explanation. Green or yellow, they are average speed cameras and the limit is enforced in the same way.
Are there average speed cameras in Wales?
Yes, Wales has average speed cameras on its main roads, and in February 2026 the Welsh Government listed exactly where they are permanent. Five locations have cameras in both directions:
- M4 junction 28 (Tredegar Park) to junction 24 (Coldra)
- M4 junction 40 (Tai Bach) to junction 42 (Earlswood), Neath Port Talbot
- A470 Upper Boat Interchange to Bridge Street Interchange, Pontypridd
- A483 junction 5 (Mold Road) to junction 6 (Gresford), Wrexham
- A494 St David's Park Interchange to Deeside Industrial Park Interchange, Flintshire
Two more sites work in the westbound direction only: the A55 at Rhuallt Hill in Denbighshire, and the A5 at Cerrigydrudion, Glasfryn. You can read how the system measures your speed in our guide to average speed cameras in the UK.
What is the speed limit on the A55?
The speed limit on the A55 for cars is 70 mph on its dual carriageway sections, unless signs show a lower limit. Most vans and anything towing have a limit of 60 mph on a dual carriageway, and lorries over 7.5 tonnes are also limited to 60 mph. On a section of single carriageway, those limits are 60 mph for cars and 50 mph for most other vehicles.
Are there speed cameras on the A55?
Yes, the A55 has westbound average speed cameras at Rhuallt Hill. They began as a trial in June 2018, after radar recorded 217,642 vehicles travelling above 70 mph in under three weeks that March. The Welsh Government says the road's gradient and alignment make it difficult to drive. A year later it reported 7 collisions, 5 fewer than the year before, and the cameras are still on its 2026 list.
Are there temporary limits on the A55 in 2026?
Yes, roadworks bring temporary limits to the A55, so check before a long trip. A Welsh Government order published in September 2026 for work at Penmaenbach Tunnel in Conwy sets temporary limits of 50, 40 and 30 mph on different lengths, along with a contraflow and a ban on overtaking. Highway Code rule 288 says you must not exceed any temporary maximum speed limit.
Will the 50 mph limits on the M4 be scrapped?
There is no announcement that the 50 mph limits are going, although the question is very much alive. Senedd Research reported in June 2026 that roadside nitrogen dioxide fell by 42 to 63 per cent between 2018 and 2024, and that pollution was below the legal threshold at all five sites in 2024. It also found that other factors seem to have played a part, so the improvement is not down to the limits alone.
- The case for change: the Senedd has accepted three petitions opposing the limits, including one completed in February 2026 with 3,334 signatures asking to return the M4 to 70 mph.
- The Welsh Government's position: Senedd Research records that the last Welsh Government said the limits would be reviewed periodically. A minister said in January 2025 that if pollution drops below the legal threshold, "then we'd look at removing those speed restrictions".
- Possible further sites: a Welsh Government page last updated in 2024 names the A470 from Coryton to Nantgarw and the M4 from junction 43 to junction 44 as two more places with high levels, and says lower limits may follow if the evidence supports them.
Until a change is announced and signed, 50 mph remains the limit. The Newport limit also has reasons beyond air quality, because it was designed to manage congestion on that stretch.
Who runs speed cameras in Wales?
GoSafe runs speed cameras in Wales. It is the Wales Road Casualty Reduction Partnership, made up of 27 equal partners: the 22 unitary authorities, the four Welsh police forces and the Welsh Government. It is responsible for fixed speed cameras, red light cameras, average speed cameras and mobile enforcement cameras.
A few details are useful for drivers in Wales:
- Where the cameras are: GoSafe publishes a camera map you can filter by local authority, maximum speed and camera type.
- What the map does not do: GoSafe notes that the absence of a camera on the map does not negate an offence.
- How sites are chosen: cameras may be placed where speeding is a concern, where there is a history of casualties, or around schools and road works.
- What mobile units check: GoSafe says its mobile cameras can detect speed, mobile phone and seatbelt offences at the same time.
GoSafe says its most successful cameras are the ones that see the fewest offences, which is a good way to think about all of this.
What is the speed limit on roads with street lights in Wales?
The speed limit on roads with street lights in Wales is generally 20 mph, unlike the 30 mph default in England and Scotland. Wales brought in the default on restricted roads in September 2023. Highway authorities can keep some roads at 30 mph, and those roads are signed, while a map on DataMapWales shows which ones remain at 30 mph.
There are no repeater signs on default 20 mph roads, so the street lights are your reminder. This matters when you leave the M4 or the A55 at the end of a long trip, because your limit can fall from 70 mph to 20 mph within minutes. GoSafe says enforcement in 20 mph areas started to return in November 2023, at existing enforcement sites that were not affected by the change and had the correct signs. Read more in our guide to 20 mph limits in Wales, London and elsewhere.
What do the Welsh limits mean for your next drive?
Coming into Wales on the M4, expect to settle at 50 mph at Newport and again at Port Talbot, and to hold it to the end of each section. In the north, take care on the climb at Rhuallt Hill, and check for works around the Conwy tunnels. Then, once you leave the main road, remember that 20 mph is the usual limit under the street lights.
Ghost is a great fit for roads like these. It runs next to Google Maps and warns you safely from the background, with a banner and a tone over your music, about 700 m ahead of known fixed speed cameras and average-speed zones. As you get closer it shows the exact distance clearly, and it alerts you again at 250 m, so you are settled at the right speed in good time. Mobile vans are a different matter, because they move and Ghost does not warn about them. It works on your phone, CarPlay, Android Auto and Apple Watch, with more than 125,000 speed cameras worldwide.
