Route
Junction number
6
Markerpost
39.5 km
Name
The Clock Interchange
Type
Non-standard interchange
Terminus
Not a terminus
Other routes
A1000, B197, B656
Authority
Restricted turns
Full access
Services
No services
A1(M) J6 The Clock Interchange
Layout and signage
|
Welwyn Welwyn Garden City A1000 |
B656 B197 |
|
B197 A1000 |
Welwyn Welwyn Garden City A1000 |
Lane configuration
- Lane 1 exits and does not return.
- Lane 2 continues ahead.
- Lane 3 continues ahead.
- Lane 1 has option to exit and splits to create a new lane.
- Lane 2 continues ahead.
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...
Harry Yeadon
A civil engineer, working principally in the North West of England, responsible for many of the area's motorways.
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