Route
Junction number
None
Markerpost
18.6 km
Name
Abercynon Roundabout
Type
Roundabout
Terminus
Not a terminus
Other routes
A472, A4054, A4059
Authority
Restricted turns
Full access
Services
No services
A470 Abercynon Roundabout
Layout and signage
|
Aberpennar Mountain Ash Aberdâr Aberdare A4059 Ystrad Mynach A472 Aberfan (A4054) |
A4059 | 
|
A4054 A472 A4054 |
Ystrad Mynach A472 Aberfan (A4054) Aberdâr Aberdare A4059 |
Lane configuration
- Lane 1 continues, with option to exit.
- Lane 2 continues, with option to exit.
- Lane 1 continues, with option to exit.
- Lane 2 continues, with option to exit.
Other events
Traffic signals
50mph speed limit begins
- Traffic signals
National Speed Limit begins
What's new
The road that made no sense
It was the UK's only single-carriageway motorway, and twenty years ago it ceased to exist. This is the story of the strange fascination it held, and of my place in history.
The forever bottleneck, part 2
The second part of the story, where we learn why exactly the M4 gets narrower on the final approach to Europe’s biggest city.
The forever bottleneck, part 1
The M4 into London was one of the UK's earliest and most ambitious motorway projects. It was bold, pioneering... and almost instantly regretted.
Have you seen...
London's Forgotten Arterial Roads
The 1920s and 30s saw a huge roadbuilding boom in London's suburbs. Some of those roads are incredibly well known, but here are five Arterial Roads that have been almost completely forgotten.
About this page
Published
Last updated
Published
Last updated
