M4 closure warning for Thames bridge work between Slough-Windsor and Maidenhead

National Highways said the upgrade between junctions 3 at Hayes and 12 at Theale, which started in 2018, was expected to finish by the end of the year

Part of the M4 motorway will shut over the weekend for work to turn it into a smart motorway.

It will close both ways between junctions 6 for Slough-Windsor and 8/9 at Maidenhead from 22:00 BST on Friday.

National Highways said the closure was for work to "resolve issues with the bridge that carries the M4 over the River Thames near Bray."

Diversions will be in place with the motorway re-opening again on Monday by 06:00.

National Highways said the work was for the final stages of the full revamp of the M4 between junctions 3 at Hayes and 12 at Theale.

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A spokesman said: "It is vital that we do this work now in order to handover a fully completed upgrade to the National Highways operations team.

"We anticipate that the project overall will be completed by the end of the year."

The next planned full weekend closure takes place between junctions 5 for Langley and 6 Slough-Windsor from 22:00 on 29 October to 31 October.

The £848m project to turn the M4 into a smart motorway started in 2018.

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.