Final closure to complete M4 smart motorway

Work started on the smart motorway scheme in 2018

A scheme to turn a section of the M4 into a smart motorway is due to be completed over the weekend.

Part of the motorway between Slough and Maidenhead in Berkshire will be closed from 22:00 GMT on Friday until 06:00 Monday.

The section between junctions 6 and 8/9 will be shut while final work is carried out on Thames Bray bridge.

National Highways said traffic would be diverted on to the A308M, the A308, the A332 and the A355.

A spokesperson said: "Variable speed limits introduced earlier this year will continue to operate on the M4, with some sections starting to return to the national speed limit.

"A new camera system is now fully operational, in addition to supplementary traffic officer patrols which will continue to monitor the road while we decommission the temporary CCTV and free recovery service."

The £848m project to turn the M4 into a smart motorway between junctions 3 at Hayes and 12 at Theale started in 2018.

• What are smart motorways and are they dangerous?

• How smart are smart motorways?

Smart motorways involve using the hard shoulder as a running lane and using variable speed limits to control the flow of traffic.

A new radar Stopped Vehicle Detection (SVD) system identifies a stopped vehicle, typically within 20 seconds.

In January, the government paused the rollout of smart motorways amid safety concerns until five years' worth of data had been collected to assess whether or not they are safe for drivers.