For Islanders planning to travel on the Mainland over Christmas and New Year, a significant motorway closure is set to affect journeys.
The M27 will close in both directions between Junctions 9 (Whiteley) and 11 (Fareham) from 8pm on 24th December 2025 until 4am on Sunday 4th January 2026.
Major engineering work
The closure will allow engineers to install a new four-lane underpass beneath the motorway using a ‘box slide’ technique.
This method removes the need for months of lane restrictions, temporary speed limits and repeated overnight works.
A huge pre-built concrete structure weighing around 8,500 tonnes, which is 2.5 times heavier than HMS Victory, will be slid 65 metres into a trench cut into the embankment on the north side of the road.
Once in place, teams will fully reconstruct the motorway above the new underpass.
Diversions and travel advice
A signed diversion will run along the A27, which has two lanes in most sections.
The route is expected to be heavily used, especially between 10am and 4pm each day, when delays are likely.
Travellers are encouraged to plan ahead and think about alternatives such as public transport, choosing quieter times of day, taking different routes or considering whether the journey is essential.
Entry and exit
Drivers will be able to exit the M27 westbound at Junction 11 for Fareham and Gosport, and eastbound at Junction 9 for Whiteley and Park Gate.
There will be no westbound entry onto the M27 at Junction 11 towards Southampton or the A32, and no eastbound entry at Junction 9 towards Portsmouth.
The closure is expected to have a notable impact on those travelling across the region during the festive period.
