Part of the M25 will be shut for a full weekend for the second time this year to continue work on an improvement scheme.

National Highways has again warned drivers to expect delays and only travel if necessary, as the new diversion routes are longer than last month

The London orbital, the UK’s busiest motorway, will close between junctions 9 and 10 in Surrey from 9pm Friday 10 May to 6am Monday 13 May 2024 – and long delays are expected.

The closure will enable a new bridge consisting of 68 beams, each weighing 16 tonnes, and another four beams weighing 40 tonnes, to be installed as part of ongoing work to make journeys safer and reduce pollution.

The M25 was previously shut over a weekend in mid-March to enable demolition of a bridge as part of the £317m Junction 10 improvement project. The closure marked the first scheduled daytime all-lanes shutdown on the M25 since it opened in 1986.

May’s closure will mark the second of five full weekend closures planned to carry out the improvements – and National Highways has again warned drivers to expect delays and only travel if necessary, as the new diversion routes are longer than last month.

Jonathan Wade, National Highways senior project manager, said: “This is far from a repeat of the previous closure, as the alternative routes are longer and will be different for over height vehicles and all other traffic.

“Drivers listened to our advice last time which reduced motorway traffic levels by over two-thirds and meant delays were limited.

“Our advice again is please only travel if absolutely necessary and make sure you give yourself extra time if you do choose to use the M25.”

The Junction 10 improvement scheme will see an increase in 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.

While last month’s closure had been expected to bring the “worst traffic jam ever”, 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.

M25 closure updates and full project information are available here.