Second full weekend closure of M25 set to cause delays for Kent motorists
Drivers are being urged to avoid the stretch near Junctions 9 to 10 as a diversion on local A roads is in place
Motorists have been warned of lengthy delays as part of the M25 closes this weekend.
The motorway - which is Britain's busiest - will be closed in both directions between junctions 9 and 10 i 9pm on Friday until 6am on Monday while concrete beams for a new bridge are installed.
It follows an earlier closure in March - the motorway's first ever planned full closure - to demolish a bridge between Junctions 10 and 11.
Saturday is predicted to see temperatures rise as high as 26C in parts of south-east England, including around London, in what would be the hottest day of the year.
AA: Avoid the area if possible
Diversion routes will take cars on a 19-mile journey on A roads between Junctions 8 (Reigate) and 10 (A3).
Drivers are being diverted along the A217 and A24 through Banstead and Ewell, before joining the A3 at Tolworth.
High vehicles, including as HGV lorries, are being diverted from Junction 9 (Leatherhead) along the A240 to Chessington, before diverting along the A309 through Esher and rejoining the A3 at Cobham.
National Highways' diversion will cross from Surrey into London's Ultra Low Emission Zone (Ulez) area, though it has assured drivers "no enforcement action will be taken".
But the highways authority said anyone who ignores official diversion signs in an attempt to find shorter alternative routes will be liable for the £12.50 daily Ulez fee if their vehicle does not meet minimum emissions standards.
Failure to pay the charge when required can result in a £180 fine, reduced to £90 if paid within 14 days.
The AA is advising drivers to plan ahead, and avoid the area completely if possible.
Speaking to Greatest Hits Radio, Patrol of the Year Chris Wood said the motoring organisation is "well prepared" for the weekend's closure.
"We do have extra patrols on shift in the area to cope with the diversion and the amount of traffic that we're expecting to see."
He warned people not to take advantage of the warm weather by planning a day trip to attractions in the area.
Mr Wood also warned people to heed National Highways warning to stick to the official diversion routes.
"These sat navs will take you into the Ultra Low Emission Zones, and we don't want drivers to get fined by driving into these zones.
"It also just keeps the traffic flowing, instead of people going into residential areas and blocking all the side streets."
The AA is also urging anyone driving into the area to conduct checks on their car, including oil and tyres, before setting off, as well as ensuring they have enough food and drink in the case they are sat in long queues.
The M25 closure is the second of five planned weekend closures which come as part of a £317 million project to improve Junction 10.