THE M25 will be closed all weekend with an urgent warning issued to drivers facing a 10-mile diversion.
It is the third of five such closures to allow for the construction of a new bridge on the western gyratory of the roundabout at Junction 10.
The busy motorway – which encircles London – will be shut between junctions 10 and 11 from 9pm Friday July 12 to 6am Monday July 15, said National Highways.
Those heading along the route to the Goodwood Festival of Speed will be diverted onto A-roads.
The festival’s organiser has warned drivers to check their route before departure.
“It may be wise to allow a little more time than planned,” it told Autocar.
Also affected will be many of those travelling to, from and between the UK’s two busiest airports, Heathrow and Gatwick.
Jonathan Wade, National Highways senior project manager, urged drivers to follow the temporary signs, saying: “Please ignore your sat-navs and follow our diversion route instead.”
National Highways has also advised drivers that avoiding the closure by heading the other way around the M25 via the Dartford Crossing may also be quicker.
The bridge will be installed as part of ongoing work to make journeys safer and reduce pollution.
It consists of 68 beams, each weighing 16 tonnes, and another four beams weighing 40 tonnes.
It is part of a £317 million project to improve Junction 10.
The March closure was the first planned daytime shutdown of the M25 since it opened in 1986.
The project, due to be completed in summer 2025, will increase the number of lanes at Junction 10, which is one of the UK’s busiest and most dangerous motorway junctions.
The full details on all diversion routes are below.
Junction 10 – Junction 11: exit the M25 at J10 and take the 3rd exit to the north bound A3 to the A245 Painshill Junction, A245 towards Woking, and Byfleet.
Then at the Six Crossroads Roundabout take the 5th exit to the A320 continuing to M25 Junction 11 where the diversion will end.
Junction 11 – Junction 10: exit the M25 at J11 and take the 3rd exit to the A320 south towards Woking, then at the Six Crossroads Roundabout take the A245 towards Byfleet.
Continue on the A245 to the A3 Painshill junction, then take the 3rd exit to the southbound A3 to Junction 10 where the diversion will end.
Avoiding the closure by taking the M25 via the Dartford Crossing may also be quicker, said National Highways.
Between 4,000 and 6,000 vehicles normally use the M25 between Junctions 9 and 11 in each direction every hour from 10am until 9pm at weekends.
The final two weekend closures as part of the project will take place later this year.
It comes as a 15-mile diversion is also in place on the M1 this weekend, with motorists facing delays of up to 40 minutes.
2024’s first closures took place on March 15, between junctions 10 and 11 in Surrey on the UK’s largest motorway.
They lasted over the weekend with the road only reopening on Monday March 17.
The second set of closures took place during a weekend in mid-May, with junctions nine and 10 shutting both ways.
Now the M25 is set to close for the third time this year, as National Highways said it will shut the motorway between Junctions 10 and 11 in Surrey from 9pm on Friday July 12 to 6am on Monday July 15.
This will be the third of five weekend closures of the motorway – which encircles London – as part of a £317 million project to improve Junction 10.
