A404(M)

A404(M)

Maidenhead Bypass

Maidenhead Thicket to Holyport

The A404(M) is a spur from the M4 to the A4 and A404 running to the west of Maidenhead, but it started life as the western terminus of the M4.

Routes

What's new

Imperfectly Odd: Batheaston Bypass

It has viaducts, a tunnel and plenty of controversy, but the amazing Batheaston Bypass doesn’t really work. What went wrong?

South London's lost motorways

Completing the story of London's epic Ringways, we've just published the Southern Radials, five more motorways that never saw the light of day.

To the north east!

Two new additions to our collection of Opening Booklets take us to Darlington and Middlesbrough.

Share this page

Have you seen...

Queensway Tunnel

The engineering marvel of its day, much altered and maligned ever since: this is the original Mersey Tunnel in all its glory.