M4 Smart Motorway

After more than four years of work a 32-mile M4 upgrade across Berkshire and London is now fully open - National Highways has confirmed today (Monday, December 5). National Highways has carried out a four-year upgrade to convert the carriageway into a Smart Motorway.

The completed Smart Motorway runs between Junction 3 (Hayes in Greater London) and Junction 12 for Theale, near Reading. The eastern section of the M4 between junctions 3 and 8/9 (Maidenhead) has now moved to 70mph - has now reopened.

The Smart Motorway scheme - which has seen years of weekend closures in Berkshire - means all lanes are running and there is no hard shoulder. There 34 new emergency areas between junctions 3 and 12 - one every 1.3 miles on average.