The M25 will be closed for a full weekend for the first time from Friday as part of National Highways’ £317m M25 Junction 10 scheme.
The government-owned company has warned motorists of long delays and advised them only to travel if necessary during what will be the first of five closures between now and September.
It will shut the M25 in both directions between junctions 10 and 11 from 9pm on Friday evening (15 March) to 6am on Monday to demolish the Clearmount bridleway bridge and install ‘a very large gantry’.
It said that without a full closure of the motorway, it would be impossible to safely carry out this work.
Project lead Jonathan Wade said: ‘We have spent months planning for these closures and making sure there are diversion routes in place, but there will still be heavy congestion and delays.’
National Highways said that it and contractor Balfour Beatty have liaised with key stakeholders in the lead up to this closure including emergency services, Surrey County Council, local businesses and Gatwick and Heathrow Airports.
However, RAC breakdown spokesperson Alice Simpson said that 'despite fair warning', most holidaymakers seeking to use either airport will have booked their trips months ago.
She said: 'With the M25 closures and the Easter getaway both falling in March, it could be a month of double traffic trouble for drivers trying to get around London or access Gatwick and Heathrow.'
The next full closure of the motorway is due to take place in April to allow for the installation of the new Clearmount bridleway bridge.
Later this year, National Highways will also look to install the new Cockcrow Green Bridge which it described as ‘the project’s centrepiece’. Connecting Ockham and Wisley commons for the first time it will be the UK’s first ever heathland bridge.
As Highways has reported, the Junction 10 scheme, which began in late 2022 and is due to run to summer 2025, has caused major jams, with nearly two million vehicle hours of delay last year.