Parts of a busy motorway junction will be closed for five weekends throughout March and April.
National Highways wants to reduce queues at M25 junction 25 for the A10 at Cheshunt.
To do this, the junction will be partially closed.
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From 10pm on Friday, March 4 until 5am on Monday, March 7, the A10 southbound will be shut between Great Eastern Way, Cheshunt and the M25 junction.
There will be no exit from Holmesdale Tunnel to the A10, and no access to the M25 clockwise towards Stansted Airport.
The eastern side of the roundabout will be closed.
These works are repeated between Friday, March 18 and Monday, March 21.
From 10pm on Friday, March 11 until 5am on Monday, March 14, the A10 northbound will be shut between the Bullsmoor Lane, Enfield traffic lights and the junction.
There will be no exit from the M25 clockwise to the A10, and no access to the M25 anticlockwise towards Watford.
The western side of the roundabout will be closed.
These works are repeated on March 25 until March 28, and again on April 8 until April 11.
A National Highways spokesperson said that the roundabout will be fully resurfaced and road markings will be repainted when the roads are closed.
They said: "There's never a good time to complete this type of work on a busy junction, and there will be some delays due to traffic in the area during the closures.
"Drivers are advised to plan and leave extra time for their journeys."
According to National Highways, around 6,300 vehicles per hour travel through the roundabout at peak times.
The organisation said that the works are needed because traffic is expected to increase by an extra 20 percent in the area by 2037.
Journey times could double if nothing is done, National Highways said.
Signs in the area say the works are due to be complete by the end of June 2022.
A webpage has been set up with more information about the roadworks: https://nationalhighways.co.uk/our-work/south-east/m25-junction-25-improvements/
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