M25 Denham - Hunton Bridge

Name
Denham Hunton Bridge
Opened
Current route
Start point
Junction number at start: 16
Denham
End point
Junction number at end: 19
Chandlers Cross
Original route

The section from J17 Maple Cross to J19 Chandlers Cross had been open as A405 since the 1970s.

Road scheme and chronology data is courtesy SABRE (where much of it was gathered by member Ross Spur), with additional data from the UK Motorway Archive, the Scottish Roads Archive and the Northern Ireland Roads Site.

In this section

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.

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