A section of the M25 in Surrey will be closed for a second time this year as improvement works continue.
The motorway will be shut between junctions nine and 10 between 10 and 13 May.
A new bridge consisting of 68 beams, each weighing 16 tonnes, and a further four beams weighing 40 tonnes are to be installed as part of project to improve safety and reduce pollution, National Highways said.
Jonathan Wade, of National Highways, urged motorists to only travel “if absolutely necessary”.
A five-mile (8km) stretch between junctions 10 and 11 was closed from 15-18 March – the first time there had been a scheduled daytime shutdown of all lanes on the M25 since it opened in 1986.
An 11.5-mile (18.5km) diversion route was created to direct traffic along nearby A roads.
Mr Wade said the May closure was “far from a repeat of the previous closure” as the alternative routes are to be longer and will differ for overheight vehicles and all other traffic.
“Drivers listened to our advice last time, which reduced motorway traffic levels by over two-thirds and meant delays were limited,” he said.
“Our advice again is please only travel if absolutely necessary and make sure you give yourself extra time if you do choose to use the M25.”
During the closure, there will be four diversionary routes, including clockwise from Gatwick towards Heathrow for most traffic and overheight vehicles.
The other two diversionary routes will be anticlockwise from Heathrow towards Gatwick for most traffic and overheight vehicles.
The upcoming work will take place during between junctions nine (A243 Leatherhead) and 10 (A3 Wisley) from 21:00 BST on 10 May until 06:00 on 13 May.
The improvement scheme, which forms part of a £317m upgrade to the motorway, will see an increase in the number of lanes to attempt to make journeys safer and a new junction layout to improve traffic flow.
The carriageway between junctions nine and 11 carries between 4,000 and 6,000 vehicles per hour in each direction between 10:00 and 21:00 on a weekend, National Highways said.
A further three closures are planned between July and the end of the year.