M25 Junction 10 / A3 Wisley Interchange Improvement Scheme

Working on behalf of National Highways, we are carrying out essential work at the M25 Junction 10 / A3 Wisley interchange to improve safety and reduce collision frequency and severity.  

The M25 Junction 10 / A3 Wisley interchange is the busiest section of the M25 with over 300,000 vehicles travelling through it every day. To improve the junction, we are building four new slip roads at Junction 10, increasing the capacity of the roundabout and widening the A3 to four lanes either side of the junction.   

As part of our scope of works we will also undertake the demolition of five bridges and construct eight new ones.  

The scheme will also involve some of the most extensive environmental works ever carried out by National Highways, restoring over 25 hectares of heathland as well as planting new woodland and constructing the UK’s first heathland green bridge. 

Minimising customer impact through off-site manufacturing 

Through modern methods of construction, we have combined cutting-edge innovation with collaborative partnerships to minimise the impact of the works on road users. 

To significantly accelerate build times and reduce the duration of on-site bridge installations, the precast concrete shells for the bridge builds are being produced off-site at our supply chain partner's manufacturing facility in Worksop. This process ensures that the shells are pre-engineered for safe deployment and manufactured in a controlled factory environment, resulting in a consistently high-quality product. It also enables us to reduce the construction working area and maintain the road capacity through the works, minimising customer impact whilst providing greater certainty on required closures and enhancing overall project efficiency. 

A first for the M25 

The first closure of the M25 since its completion in 1986 took place in March 2024, and it was a great success with the junction reopening seven hours ahead of schedule. This was testament to the collaborative work undertaken by our project team with National Highways, our supply chain partners and our local stakeholders including Surrey County Council, Connect Plus Services and the emergency services. 

Collaborating with project stakeholders  

To minimise disruption across the surrounding road network, our team is working closely with National Highways and the local stakeholders who are impacted by our works. This collaborative approach has seen the team establish two-way transparent relationships with all key stakeholders ensuring they are kept fully up to date on all our activities.  

This includes RHS Garden Wisley whose annual flower show event has run smoothly over the past two years thanks to the bespoke traffic management solution developed in collaboration with them and other key local stakeholders. 

Enhancing safety with a corridor for wildlife 

To create safer routes for pedestrians, cyclists and horse riders, we are constructing the UK’s first heathland green bridge. Spanning a 30-metre-wide deck, the bridge will reconnect Ockham and Wisley common either side of the A3, creating a natural and safe corridor for wildlife whilst reducing the likelihood of animal-related incidents.

Making a positive social impact 

The scheme is dedicated to creating a lasting positive legacy and giving back to the local community. As of August 2024, the scheme has: 

  • Spent over £93 million with local businesses 
  • Made over £30,000 of charitable donations and in-kind contributions 
  • Undertaken 3,197 hours of volunteering with local community projects including children’s hospices and homelessness charities 

To inspire and support the next generation of experts to work in our industry, we have delivered 59 schools and college events, hosted 31 weeks of work experience placements, and recruited 25 apprentices and graduates.