M25 junction 23

The project aims to increase capacity at junction 23 of the M25.

Region:  South East
Start date:  July 2019
Cost:  ÂŁ7.5 million
Status:  PLANNED
Type:  Improvement Scheme
End date:  August 2020
Programme:  

Progress report

The detailed design was completed in February 2019. Subsequently, we've gone through a procurement process to agree a price to complete the works. This process is now complete, with the contractor proposing to start works in July 2019.

What's next?

We're in the process of informing all neighbouring residents and businesses of the proposed works and will continue to keep stakeholders informed during the works.

Timeline

Event Date
Complete detailed design February 2019
Start of construction works July 2019
Planned completion of the works August 2020

Why we need this scheme

The M25 junction 23 is controlled by traffic signals, and is where the M25, A1, A1(M) and A1081 meet. Junction 23 is operating over its design capacity, which leads to congestion, queuing traffic and journey delays during peak hours. The junction 23 scheme also provides for safety improvements within its design.

Aims

Proposed improvements

  • Widening of the A1 southbound merge slip road to provide a two-lane entry to the A1 south
  • New footway for pedestrians from the BP service station to the existing footway adjacent to the roundabout
  • Upgrade the traffic signal timings to improve traffic flow through the junction
  • A new lane at the Bignells Corner exit from South Mimms services
  • Widening of the M25 westbound exit slip road to accommodate an additional lane on the approach to the junction to reduce congestion
  • Updated road signs to reflect the new road layout

Benefits

  • Safer network – reduced accident rates, improved signs and road markings to encourage good lane discipline, improved provision for pedestrians and cyclists
  • More free-flowing network – reduced congestion and more reliable journey times

Environmental impact

The scheme is expected to have only minor environmental impacts:

  • The scheme is adjacent to the northerly boundary of The Mimms Caravan Park and hotels within South Mimms Services. There will be some construction activities that will cause noise and vibration. There will be measures in place to reduce impacts as far as is possible. Where possible the noisiest activities will be programmed during the day.
  • The works will be over part of Clarehall Brook and the scheme includes realignment of the surface water drainage system. The new drainage design is subject to the approval of the Environment Agency.
  • The drainage realignment entails rerouting one the existing outfall points into the Clarehall Brook to a new upstream discharge point. The outfall design is being done in conjunction with the Environment Agency to ensure that it integrates into the landscape as well providing the required hydraulic performance.
  • The site is assessed as suitable for great crested newts and common species of reptile. Any suitable habitat within the working areas will be dismantled by hand and an Ecologist will be on site when required during the works.
  • Deciduous woodlands and hedgerow habitat present within the site will be excluded from the works area, delineated by Heras fencing and avoided during the works.
  • An otter ramp within the roundabout will be protected from the works.

Project media files and documents

There are no images for this project
There are no videos for this project

Project timeline

Planned roadworks

Roadworks and Events for England

The latest incident information for England's motorway and trunk routes provided by Highways England

Location : The A1M southbound between junctions J7 and J6 . Lane Closures : Lane one will be closed. Reason : Road repairs are planned. Status : Pending. Schedule : From 21:00 on 22 August 2019 to 05:00 on 23 August 2019. Lanes Closed : There will be one of three lanes closed.
Posted: August 20, 2019, 2:02 pm
Location : The A1M southbound exit slip at junction J6 . Reason : Road repairs are planned. Status : Pending. Schedule : From 21:00 on 22 August 2019 to 05:00 on 23 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 2:02 pm
Location : The M25 clockwise between junctions J22 and J23 . Lane Closures : Lane one will be closed. Reason : Emergency barrier repairs are planned. Status : Pending. Schedule : From 23:00 on 23 August 2019 to 05:00 on 24 August 2019. Lanes Closed : There will be one of four lanes closed.
Posted: August 20, 2019, 12:53 pm
Location : The A1 southbound entry slip from the M25 . Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 19 August 2019 to 23 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise between junctions J20 and J21A . Lane Closures : Lanes 1, 2, 3 and 4 will be closed. Reason : Road repairs are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 21 August 2019 to 23 August 2019. Schedule : Expect disruption everyday between 22:00 and 05:30 from 27 August 2019 to 30 August 2019. Schedule : From 23:00 on 30 August 2019 to 06:00 on 31 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The A1M southbound exit slip at junction J1 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 23 August 2019. Lanes Closed : There will be one of two lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The A1M southbound between junctions J3 and J1 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 23 August 2019. Lanes Closed : There will be one of two lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The A1 southbound between the junctions with the M25 and the A5135 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 23 August 2019. Lanes Closed : There will be one of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise between junctions J24 and J23 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 23 August 2019. Schedule : Expect disruption everyday between 22:00 and 05:30 from 27 August 2019 to 29 August 2019. Lanes Closed : There will be two of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise between junctions J23 and J24 . Lane Closures : Lane three will be closed. Reason : Emergency roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:00 from 20 August 2019 to 23 August 2019. Schedule : Expect disruption everyday between 22:00 and 05:00 from 27 August 2019 to 30 August 2019. Schedule : From 23:00 on 30 August 2019 to 05:00 on 31 August 2019. Lanes Closed : There will be one of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise exit slip at junction J21 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency road marking works are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The A1M southbound between junctions J6 and J4 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency roadworks are planned. Status : Pending. Schedule : From 22:00 on 22 August 2019 to 05:00 on 23 August 2019. Lanes Closed : There will be two of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise between junctions J18 and J19 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency barrier repairs are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : There will be two of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The A1M southbound between junctions J3 and J1 . Lane Closures : Lane one will be closed. Reason : Barrier repairs are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:00 from 20 August 2019 to 23 August 2019. Lanes Closed : There will be one of two lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise at junction J21 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency road marking works are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : There will be two of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The A414 westbound between the junctions with the A405 and the M1 . Lane Closures : The hard shoulder is closed. Reason : Emergency roadworks. Status : Currently Active. Period : expect disruption until 06:00 on 29 December 2019.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise between junctions J24 and J25 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:30 on 21 August 2019. Lanes Closed : There will be three of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The A414 eastbound between the junctions with the M1 and the A405 . Lane Closures : The hard shoulder is closed. Reason : Emergency roadworks. Status : Currently Active. Period : expect disruption until 06:00 on 29 December 2019.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise at junction J25 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:30 on 21 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The M1 southbound entry slip at junction J5 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadside drains works are planned. Status : Pending. Schedule : From 22:00 on 22 August 2019 to 05:30 on 23 August 2019. Schedule : From 22:00 on 27 August 2019 to 05:30 on 28 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise exit slip at junction J23 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 23 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise entry slip at junction J21 . Lane Closures : Lane two will be closed. Reason : Road repairs are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 21 August 2019 to 23 August 2019. Schedule : Expect disruption everyday between 22:00 and 05:30 from 27 August 2019 to 30 August 2019. Schedule : From 23:00 on 30 August 2019 to 06:00 on 31 August 2019. Lanes Closed : There will be one of two lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise between junctions J21A and J22 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Emergency roadworks are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : There will be three of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M1 southbound between junctions J9 and J8 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Emergency roadside equipment maintenance is planned. Status : Pending. Schedule : From 22:00 on 22 August 2019 to 05:00 on 23 August 2019. Lanes Closed : There will be three of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M1 southbound between junctions J6 and J4 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadside drains works are planned. Status : Pending. Schedule : From 22:00 on 22 August 2019 to 05:30 on 23 August 2019. Schedule : From 22:00 on 27 August 2019 to 05:30 on 28 August 2019. Lanes Closed : There will be two of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise at junction J21 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency road marking works are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : There will be two of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M1 northbound between junctions J1 and J4 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadside drains works are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 22 August 2019. Lanes Closed : There will be two of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise exit slip at junction J25 . Reason : Roadworks are planned. Status : Pending. Schedule : From 22:00 on 19 August 2019 to 05:00 on 20 August 2019. Schedule : From 22:00 on 20 August 2019 to 05:30 on 21 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The M1 northbound entry slip at junction J6A . Lane Closures : Lanes 1, 2, 3 and 4 will be closed. Reason : Emergency road marking works are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise exit slip at junction J21 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency road marking works are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : All lanes will be closed.
Posted: August 20, 2019, 10:23 am
Location : The M1 northbound between junctions J1 and J5 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : There will be two of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise between junctions J20 and J21 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency road marking works are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : There will be two of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise exit slip at junction J25 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 23 August 2019. Lanes Closed : There will be one of two lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise between junctions J22 and J21A . Lane Closures : Lanes 1 and 2 will be closed. Reason : Emergency road marking works are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:00 on 21 August 2019. Lanes Closed : There will be two of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise at junction J23 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 20 August 2019 to 23 August 2019. Schedule : Expect disruption everyday between 22:00 and 05:30 from 27 August 2019 to 29 August 2019. Lanes Closed : There will be two of three lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise between junctions J24 and J23 . Reason : Roadworks scheme. Status : Currently Active. Period : from 22:02 on 19 August 2019 to 05:30 on 29 August 2019.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise exit slip at junction J23 . Lane Closures : Lane two will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 22:00 and 05:30 from 21 August 2019 to 23 August 2019. Schedule : From 22:00 on 27 August 2019 to 05:30 on 28 August 2019. Lanes Closed : There will be one of two lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise between junctions J25 and J24 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Emergency barrier repairs are planned. Status : Pending. Schedule : From 23:00 on 23 August 2019 to 05:00 on 24 August 2019. Lanes Closed : There will be three of four lanes closed.
Posted: August 20, 2019, 10:23 am
Location : The M25 anticlockwise exit slip at junction J23 . Reason : Roadworks. Status : Currently Active. Period : expect disruption until 00:01 on 26 January 2020.
Posted: August 20, 2019, 10:23 am
Location : The M25 clockwise between junctions J25 and J26 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 22:00 on 20 August 2019 to 05:30 on 21 August 2019. Lanes Closed : There will be three of four lanes closed.
Posted: August 20, 2019, 10:23 am

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