Drivers are being warned again to expect delays and only travel if necessary near junctions 9-10 on the M25 from tonight.

The closure will allow a bridge consisting of 68 beams, each weighing 16 tonnes, and another four beams weighing 40 tonnes, to be installed

The 10-mile stretch between the two junctions will be closed in both directions from 9pm (Friday 10 May) and is scheduled to reopen on Monday 13 May at 6am.

It’s the second of five planned closures for improvements – and as with the first closure in March, National Highways has warned drivers to follow its official advice rather than satellite navigation system diversions to minimise congestion.

A 19-mile diversion route will be in place which uses the A3 and the A240. However, drivers in an overheight vehicle must follow a different diversion route to avoid a low bridge. Each route will be clearly signposted – details are here.

Drivers using the signed diversion route will not be subject to any Ultra Low Emission Zone charges that may usually apply – but the Ultra Low Emission Zone will remain in force on all other routes in London across the weekend and drivers are warned to be aware of this if deviating from the official route.

The closure in March – the first scheduled daytime all-lanes shutdown on the M25 since it opened in 1986 – had been expected to bring the “worst traffic jam ever”, but delays were largely minimal due to many drivers avoiding the area or rethinking plans. The work was completed eight hours ahead of schedule, which meant the section between junctions 10 and 11 was reopened to traffic early.

The £317m Junction 10 improvement scheme will increase the number of lanes to make journeys safer and new junction layout to improve traffic flow. It will also make it easier and safer to enter and exit the M25, and reduce the pollution caused by traffic jams.

A further three M25 closures are due between July and the end of the year – the date of the third closure will be announced as soon as possible after the motorway reopens on 13 May. The finished scheme is due to open to traffic in summer 2025.

M25 closure updates and full project information are available here.