Drivers using the M25 are facing significant disruption next year as National Highways has announced a full weekend closure of a key section of the motorway in March 2025. This will be only the second time in the M25's history that a full carriageway closure has been implemented, following a similar closure earlier this year. The closure, impacting the stretch between Junctions 10 (A3 Wisley) and 11 (A320 Chertsey), is essential for the demolition of the Clearmount Arch bridge as part of the ongoing Junction 10 upgrade project.
The exact dates for the March 2025 closure are yet to be confirmed, but National Highways has indicated it will take place over a full weekend. The previous full closure in March 2024, between Junctions 10 and 11, saw a five-mile stretch shut down for concrete gantry installation. While that closure was deemed a success by National Highways, with traffic largely following diversion routes, the upcoming works present a similar logistical challenge for motorists and transport planners.
The Junction 10 upgrade, a multi-million-pound project, aims to improve safety and reduce congestion at one of the busiest interchanges in the UK. This involves creating a new junction layout, including new slip roads and a larger roundabout. The demolition of existing structures, such as the Clearmount Arch bridge, is a critical phase in enabling these improvements to progress.
National Highways has stated that extensive diversion routes will be put in place to guide traffic around the closed section. However, given the M25's role as a vital artery for the South East, significant delays are anticipated on these alternative routes, particularly for long-distance journeys. Motorists are being advised to plan ahead, allow extra time for travel, or consider alternative modes of transport if possible during the closure period.
The announcement underscores the scale of infrastructure investment required to maintain and upgrade the UK's road network. While such closures are disruptive, they are presented by National Highways as unavoidable for the long-term benefits of improved road safety and efficiency. The government's Department for Transport continues to oversee these major road projects, aiming to support economic growth and connectivity across the country.