M25 to fully close for a further two weekends

National Highways has revealed that the M25 will be fully closed for a further two weekends in 2025 after being closed fully for the first time this year.  

Dates when the closures will take place are yet to be announced.

The major project to improve the busiest junction of the M25 has taken huge strides forward, with two new bridges put into place.

The completion of the structures, along with new access arrangements for the A3, represents a significant milestone in the work to upgrade junction 10 of the motorway. 

The Clearmount bridge – a bridleway offering safe passage for pedestrians, cyclists and horse-riders over the motorway – was jacked into place last weekend (November 2-3) having been constructed off-site during the summer. 

Construction began back in August 2024 and the 450 tonne steel and concrete structure was positioned alongside the M25 for two months until the abutments on either side of the motorway were constructed. 

Meanwhile, work has also now been completed on the Wisley Lane bridge which will open to traffic on Monday (November 11), and marks one of the scheme’s first large-scale accomplishments. 

Daniel Kittredge, National Highways senior project manager, said: “The opening of the Clearmount and Wisley Lane bridges are significant milestones for the M25 Junction 10 project, which will help reduce congestion, create a smoother flow of traffic and provide safer journeys for thousands every day.” 

The original Clearmount bridge was demolished during the first full weekend closure of the M25 in March as it was not long enough to span the new slip roads.

“This new bridge will be wider and provide an improved way for people to navigate over the M25 by foot, bike or horseback,” he added. 

Last weekend, the 61-metre long Clearmount bridge was jacked up to its maximum height and placed on self-propelled modular transporters (SPMT).  

The SPMTs then carefully slid the bridge onto the carriageway and moved it sideways 300 metres along the M25 and into place, with the road reopening to traffic more than two hours ahead of schedule once it was safely installed.  

This was the first time this method of transporting an already constructed bridge into place on the M25 has been used – meaning a full weekend closure of the M25 was not required. The bridge will be opened at a later date. 

Drivers are urged to take care through the junction as the configuration has changed. This will be the position until further new bridges are installed in 2025. 

The M25 Junction 10 improvement project will also see changes to the gyratory and work to install further bridges, including the green bridge at Cockcrow, as well as some gantries. 

Furthermore, heathland will be restored and new trees and woodland will be planted in other areas as part of the scheme’s pledge to make environmental improvements.