Route
Junction number
None
Markerpost
28.5 km
Name
Black Cat Roundabout
Type
Roundabout
Terminus
Terminus at top of exit list
Other routes
A1
Authority
Restricted turns
Full access
Services
No services
A421 Black Cat Roundabout
60mph speed limit begins
National Speed Limit beginsWhat'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...
A1(M) Darlington Bypass
Opened in May 1965, the A1(M) Darlington Bypass was one of the UK's earliest motorways and made huge strides in linking the North East to the rest of England. Explore the pioneering spirit of its engineers in the book they produced to mark its opening.
About this page
Published
Last updated
Published
Last updated
