M40 J1 Denham Roundabout

Layout and signage

N/A   A412



A4020


    A40






  Central London
A40
Slough
(A412)
Uxbridge
(A4020)

Lane configuration

LanesLanesLanesLanesLanes

  • Lane 1 exits and returns after the junction.
  • Lane 2 continues ahead.
  • Lane 3 continues ahead.

LanesLanesLanesLanesLanes

  • Lane 1 continues, with option to exit.
  • Lane 2 continues ahead.
  • Lane 3 continues ahead.

Other events

  • Signs Start of motorway regulations
  • Signs End of motorway regulations

In this section

What's new

Red, white and blue

Kent County Council is run by eurosceptic nationalists. So why are they putting EU flags on their road signs?

The sunlit uplands

On Saturday 31 May something historic happened. The Heads of the Valleys Road was finally complete.

Grand openings

Our much-loved Opening Booklets section has two new publications for you to explore, and we’re making some overdue changes to make them easier to find and easier to read.

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Have you seen...

Alley by gaslight

Some of Central London's quieter streets are still, surprisingly, lit by old and rather beautiful gas lanterns. Here are a few, by day and by night.

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