Project profile: M25 junction 10

The three-year project, due for completion in summer 2025, will reduce congestion, create a smoother flow of traffic and provide safer journeys for thousands every day.

M25 junction 10 project profile

Location: A few miles north of Guildford in Surrey

Project managed by: National Highways

Status: Work in progress

What stage is it at?

The project reached a key landmark in March with the demolition of Clearmount Bridge, the first of several demolitions scheduled to take place during 2024.

The demolition involved a full weekend closure of the junction, and produced 3,000 tonnes of material, which took 80 trucks more than 24 hours to clear away.

We also installed a huge gantry that spans the width of the M25. At 58 metres long and weighing nearly 130 tonnes, we needed a 70-tonne crane to lift it.

Largely thanks to many drivers avoiding the area and making other travel plans during the closure, the operation was a great success and we were able to re-open the junction ahead of schedule.

Our gallery shows the main stages of the demolition of Clearmount Bridge and the installation of the superspan gantry, which took place over the weekend 15 to 17 March.

A second weekend closure took place in May. It allowed for the installation of a new bridge consisting of 68 beams, each weighing 16 tonnes, and another four beams weighing 40 tonnes.

The closure was in place from 9pm on Friday 10 May. Due to good progress being made throughout the weekend by the project team, we were able to reopen the road on Sunday evening, seven hours ahead of schedule.

What happens next?

Between now and this autumn we’ll be closing the M25 around this junction again to demolish three bridges and install three new ones, including the UK’s first heathland bridge.

The following graphic shows the bridges to be constructed and demolished as part of the project. Blue bridges are to be constructed; red bridges are to be demolished.

Graphic showing bridges and gantries

1 Wisley Lane footbridge

2 Wisley Lane / NMU bridge

3 Cockcrow bridleway bridge

4 Cockcrow green bridge 

5 Redhill Road bridleway bridge

6 Clearmount bridleway bridge

7 Clearmount bridleway bridge

8 Northern gyratory bridge

9 Northern gyratory bridge

10 Southern gyratory bridge

11 Southern gyratory bridge

12 Sandpit Hill NMU bridge

Please check the M25 junction 10 project page for latest information about forthcoming closures and diversion routes.

What is the project?

The three-year project, due for completion in summer 2025, will reduce congestion, create a smoother flow of traffic and provide safer journeys for thousands every day.

We’ll also deliver environmental improvements, including the restoration of heathland around junction 10, and the planting of new trees and woodland in other areas.

The A3 will be surfaced with a low-noise material and environmental barriers along the M25 will be replaced. The effects on air quality will be minimised, and local rivers, lakes and ponds will be better protected from pollution and flooding.

Exploring the area on bicycle, foot or horse will be easier, with new bridges crossing the A3 and M25, connecting the four quadrants surrounding junction 10 for the first time.

Key features of the scheme:

  • An additional lane on the A3 in both directions from Ockham and Painshill junctions towards the M25
  • A larger roundabout with extra lanes to increase capacity
  • Free-flow left turns at all four corners of the junction
  • Improvements to the A245 Seven Hills junction and Painshill roundabout
  • Safer access to Old Lane, Elm Lane, Heyswood campsite and San Domenico
  • Improvements to the local environment and wildlife
  • New and safer routes for cyclists, pedestrians and horse-riders

Artist's impression of the new heathland bridge

The UK’s first heathland green bridge will reconnect the commons either side of the A3, and provide a natural and safe corridor for wildlife.

About the junction

The M25 junction 10 and A3 Wisley interchange is the busiest section of the M25, with over 300,000 vehicles travelling through it every day. Journeys that include commuters, businesses, those visiting local attractions and holiday makers.

This sheer volume of traffic means vehicles often start queuing northbound between Ockham Park roundabout and the M25 junction 10, on the junction 10 roundabout, and on the approach to the Painshill roundabout.

The junction is located among some rare and beautiful habitats including the heathland at Wisley and Ockham commons.