National Highways has lifted the M25 junction 3 inner lane closure after queues on 2 November. Its revised plan starts on Saturday 7 November. The new dates.

The 24-hour lane closure at Swanley Interchange has been taken off, days into a planned seven-week run. National Highways says congestion on Monday 2 November was higher than it expected.

The inner lane of the M25 junction 3 roundabout was due to stay shut until 18 December while the traffic lights are replaced. That timetable no longer stands. National Highways says the closure “has been removed while we review the traffic management arrangements for the scheme”. (National Highways, south east maintenance schemes)

We reported the original timetable on 31 October, from the letter National Highways sent to residents. That report has now been corrected.

The revised plan

National Highways’ scheme page now sets out this plan:

  • Saturday 7 November, 11pm to 5.30am: the northern half of the roundabout closes so temporary traffic signals can be installed.
  • After that: the temporary signals “will be monitored and signal timings adjusted where necessary before any further traffic management is introduced”.
  • Phase 1, to 18 December: arrangements are “currently under review”, with details to follow.
  • Christmas and New Year: traffic management comes off, so the roundabout is back to full capacity.
  • Phase 2, January to March 2027: regular overnight closures from 10pm to 6am, one section of the roundabout at a time.

No date has been given for any return of the inner lane closure.

National Highways’ two records differ on this weekend. Its seven-day closure report, read this evening, gives the Saturday closure as 11pm to 6am. It also lists the southern half closing on Sunday 8 November, 10.30pm to 5.30am. The scheme page does not mention a Sunday closure. If you drive through late on Sunday, check before you set off.

Why it went wrong

Laura Trott, the MP for Sevenoaks, gave her account in a public statement. She said National Highways had told her that “due to fog on Friday they were unable to put in place the temporary traffic management - but still put in the lane closure”. She said the company accepted that should not have happened and had apologised.

She also said the traffic management would go in over the coming weekend, without a lane closure at first, so traffic flows could be monitored. That matches the scheme page.

Cllr Michael Horwood, the Mayor of Swanley, said in his own statement that some residents had reported delays of more than three hours that morning. He also said National Highways’ traffic impact assessment had predicted a “minor to moderate impact” from the lane closure.

National Highways’ own page does not mention fog. It gives “higher levels of congestion than anticipated” as the reason.

Why the work still has to happen

The signals are more than 20 years old, National Highways told residents in its letter. Swanley Town Council says the contractor told it the old system cannot be repaired because the parts are no longer made. That, the council said, is why some of the lights have been out of action for an extended period. (Swanley Town Council)

What it means for you

  • This week: all lanes on the roundabout are open, on National Highways’ account.
  • Saturday night: the northern half is shut from 11pm. Use the signed diversion map and pick your route.
  • From next week: temporary signals may change how the junction runs, and timings may be adjusted. A lane closure could still come back, so check before a tight journey.
  • Questions: the National Highways contact centre is on 0300 123 5000, 24 hours a day.

National Highways warns that closures can change at short notice. Our Sevenoaks roadworks page carries this and every other booked closure in the district.

Sources

Image: The M20/M25 interchange, Swanley. Photo by David Howard, CC BY-SA 2.0, via Geograph