M25 junction 10/A3 Wisley interchange improvement scheme

Closed 6 Feb 2017

Opened 5 Dec 2016

Results updated 29 Nov 2017

We have selected Option 14 as the preferred solution for the M25 junction 10/A3 Wisley interchange improvement scheme.

Acting upon the feedback from the consultation and ongoing engagement with a range of stakeholders, design changes have enabled the elongated roundabout to improve safety by removing the need for traffic lights on the left turn slip roads (as had been included in the designs shown at the non-statutory public consultation).

We have the opportunity to provide improved crossing points for pedestrians, cyclists and horse riders on dedicated bridges, separated from the traffic, minimising the risk of collisions. The detail of these will be presented at the statutory consultation in 2018.

Minimising the environmental impact of the elongated roundabout has been a critical factor in choosing the preferred option for M25 junction 10. The area is of significant environmental value and includes scheduled monuments, access land for walkers and horse riders and land that supports rare bird species.

Highways England therefore believes the improved Option 14 and its supporting environmental mitigation provides the best solution in terms of meeting safety, traffic and environmental needs.

Side road options

This scheme will also deliver the widening of the A3 between Ockham Junction and Painshill Junction from 3 to 4 lanes. As such direct access to the A3 between these junctions will be stopped up.

Highways England has undertaken extensive engagement with stakeholders and landowners about the access arrangements to the A3, between Ockham Junction and Painshill Junction.

The key factor in our decision-making has been the safety of all road users, in particular ensuring there is no conflict between vehicles directly entering and exiting what will be a 4-lane, high speed section of the A3.

The land surrounding M25 junction 10 and the A3 presents a number of challenges for developing the scheme, notably the sensitive environmental and heritage features including:

  • Site of Special Scientific Interest (SSSI)
  • Special Protection Area (SPA)
  • Ancient woodland
  • Scheduled monuments
  • Listed buildings and registered park and gardens
  • Common land and access land
  • Green belt

These constraints make the development of side road access arrangements challenging, but we believe that the preferred options offer the best solution for all users.

The side road preferred routes can be found in our preferred route announcement brochure below.



We want your views on our plans to improve the M25 junction 10/A3 Wisley interchange to tackle issues including congestion, capacity, safety, noise and environmental impacts.

The 2 options which this consultation is seeking views on are:

  • Option 9 – a new fl yover to link right-turning movements from the A3 onto the M25
  • Option 14 – enlarging the existing roundabout, to add more capacity

We are also looking at the A3 between Ockham and Painshill. Improvements could include widening parts of the A3 to 4 lanes, creating an extra lane for vehicles turning left onto the A245 at the Painshill roundabout, and changing local accesses to make these safer and cause fewer delays on the A3.

Why your views matter

This section of the M25 is of nationally-strategic importance, as it is vital for access to and from Heathrow and is a key route from the Kent ports to much of the rest of the country. The cost to the economy of ongoing delays here would be considerable if left unchanged.

The A3, which is the key route between London and Portsmouth, intersects the M25 at junction 10, and has its own issues with traffic flow. Painshill interchange, to the north of the junction, creates a pinch-point or bottleneck, because its current layout and proximity to junction 10 restricts traffic flow through the area.

The M25 junction 10/A3 Wisley interchange has been identifi ed for improvements as it experiences heavy congestion on a daily basis. This causes queues and prevents access from Ockham Park junction (A3) to the M25 junction 10 and on to Painshill junction (A3) in both directions. A similar problem is experienced by traffic entering and exiting the M25 junction 10/A3 Wisley interchange. The area around the M25 junction 10/A3 Wisley interchange has the highest recorded collision rate across the Highways England network.

This consultation aims to get your views on 2 potential options for improvements. A number of other options have also been looked at but they either fail to reduce congestion or improve safety, or have a very signifi cant impact on the surrounding environment.

Details on the 2 options, with maps, are contained in the scheme brochure.

Once we have analysed your feedback, a preferred route will be chosen and more detailed plans will be developed. You will have a further opportunity to give feedback via public consultation once the preferred route is announced – this is expected to be in late 2017.


  • All members of the public


  • Roads