M25 junction 25 improvements

Upgrade of junction 25 on the M25 to provide greater capacity.

Start date 2020-21
End date TBC
Cost £25 million to £50 million

Latest updates

  • 06 January 2022

    January overnight and weekend closures - plan ahead

    Central reservation replacement

    In the New Year, we’ll be working on replacing the central reservation barriers on the A10, to the north of the junction. To allow us to do this safely there will be overnight lane closures on the A10 between the junction and Great Eastern Way. The closures will in place between 10pm and 5am from Monday 17 January up to and including Friday 21 January

    Although no full closures are in place, there may be additional traffic in the area due to the lanes closures, so please take this into consideration when planning your journey.


    We’ll also be resurfacing the junction over two weekends. To safely carry out these works we’ll be closing the A10 southbound, between Great Eastern Way and junction 25, the northern part of junction and also the Holmesdale Tunnel exit slip road from:

    10pm Friday 14 January to 5am Monday 17 January

    10pm Friday 28 January to 5am Monday 31 January

    A10 southbound diversion

    If you’re travelling southbound on the A10 towards junction 25, you will be directed to the local diversion starting at the Lieutenant Ellis Way roundabout, onto Winston Churchill Way, onto Monarchs Way, onto A1010 and then turn right onto Carterhatch Lane to join the A10 south of the junction.

    Traffic wanting to access the M25 from this direction should follow the above diversion up to the Monarchs Way junction, join the A121 and follow to then join the M25 at junction 26.

    Northern part of the junction diversion

    If you’re travelling clockwise on the M25 and want to reach Enfield, there will be a diversion in place taking you north on the A10, at the first roundabout turn onto Winston Churchill Way, onto Monarchs Way, onto A1010 and then turn right onto Carterhatch Lane to join the A10 south of the junction.

    Traffic coming from Enfield looking to join the M25 clockwise will also need to use the diversion in place taking you north on the A10 to the roundabout at the junction of Lieutenant Ellis Way and Winston Churchill Way, onto the A121 to join the motorway at junction 26.

    Alternatively, you can join the M25 anti-clockwise using the junction 25 anti-clockwise entry slip, turn off at junction 24 exit slip, turn around, take the M25 clockwise entry slip and continue along the M25 clockwise.

    Holmesdale Tunnel exit slip diversion

    If you’re travelling anti-clockwise on the M25, continue up to junction 24, turn around at the junction and take the M25 clockwise entry slip, turn off at the junction 25 exit slip, A10 northbound, at the Lieutenant Ellis Way roundabout turn right onto Winston Churchill Way, onto Monarchs Way, onto A1010 and then turn right onto Carterhatch Lane to join the A10 south of the junction.

    CCS rate us as ‘excellent’!

    A recent independent audit by the CCS (Considerate Constructors Scheme) found our site to be excellent, after we achieved a score of 40 out of 45.  

    You can find out more about the visit here.

  • 21 January 2021

    Virtual public information event – how to join

    Due to the pandemic and lockdown, we're hosting an online virtual public information event, where you'll be able to view detailed information about the scheme, and ask our project team questions.

    Our team will be available on the following dates:

    Monday 25 January: 8am – 12pm and 2pm – 6pm

    Friday 29 January: 11am – 3pm

    Saturday 30 January: 9am – 12pm

    The link to the virtual room will appear here at 8am on Monday 25 January.

    Join the virtual event


    Project now under way

    We’ve begun preparation works by starting to install our site compound and are building an access track for construction vehicles, with the main construction works to begin in February.

    To keep up-to-date with the scheme progress, please sign up for updates on the right hand side of this page.

  • 24 January 2020

    Detailed design process

    We'll now progress with the detailed design of this scheme through the course of 2020. Scheme construction will then begin in winter 2020-21. Email updates on progression during scheme construction will then be sent to all those who have registered to receive project updates with the scheme webpage.

  • 25 June 2019

    End of Public Information Exhibition period

    The Public Information Exhibition period closed on 24 June 2019.

    The Public Information Exhibition was announced from 20 May 2019 onwards following on from the previous communication milestones. The purpose of the PIEs was to:

    • inform stakeholders of the progress we had made since the PRA
    • describe what would happen next
    • share our initial understanding of potential traffic impacts during construction
    • provide further opportunity to meet the team and ask any questions

    The majority of feedback was regarding the following themes/topics

    • Construction: when the work will start, finish and its duration
    • Discounted options/design decisions
    • How the scheme will operate

Project information

Give us your feedback

Visit our M25 Junction 25 Improvement Scheme feedback tool to have your say. The tool includes an interactive map. You can click on a location to make a specific comment, or give us your general feedback.

ECHO is a one-way feedback tool, so if you’d like a response to your feedback you can email the project team at: M25j25@highwaysengland.co.uk

Junction 25 is a nationally and regionally important road, connecting the M25 with the A10. Up to 6,300 vehicles per hour currently travel through the junction 25 roundabout at peak times, causing congestion and regular delays. The A10 southbound approach into the junction is also a congestion hotspot in Broxbourne.

Our research shows that if we don’t improve junction 25 by 2037, we can expect:

  • increased congestion and lengthy queues and journey times could double
  • average speeds could reduce by up to 30% through the junction
  • disruption would be more widespread following incidents
  • congestion would constrain future development and growth opportunities
  • uncontrolled deterioration to local air quality

Detailed information about the scheme was presented at our virtual engagement event held in early 2021. 

Through this scheme, we aim to:

  • reduce congestion and delays at junction 25 between the M25 and the A10
  • increase capacity by widening both the roundabout and the A10 southbound approach
  • redesign the roundabout to improve safety and traffic flow
  • support future traffic demands, enabling development and economic growth
  • maintain access for pedestrians and cyclists and improve conditions where possible
  • minimise the environmental effects of this scheme on local air quality and noise


Traffic information

Information about scheduled roadworks and events on our motorways and major roads.

Sign up for updates!

Keep up to date with what's happening on this scheme by signing up to our updates.