Progress on new underpass beneath the M27 in Hampshire
The upgraded junction ten is set to open late next year
A huge concrete structure is being slid into place on the M27 in Hampshire’s first ever ‘box slide’ operation.
The new underpass at junction 10 is due to open in late 2026, with hopes it will ease journeys in the area.
A road closure is due to remain in place until 4am on 4th January, and Hampshire County Council has advised drivers to plan ahead for travel disruptions, avoid the area if possible, and use alternative routes or modes of transport.
A signed diversion route will guide road users via the A27, although drivers have been told to expect severe delays, particularly between 10am and 4pm.
The works involve removing parts of the motorway and embankments to slide in an 8,500-tonne pre-constructed concrete box that will form a new underpass beneath the M27.
The project is part of Hampshire County Council’s M27 Junction 10 improvement scheme designed to create an ‘all-moves’ motorway junction, improving access between Fareham and the Welborne Garden Village development that is anticipated to deliver up to 6,000 new homes as well as new schools and community services. It is expected to open to traffic in winter 2026.
Councillor Lulu Bowerman, Hampshire County Council's Cabinet Member for Highways, said: “We appreciate this will cause disruption and thank everyone for their understanding as we deliver these vital improvements.”
Andrew Jackson, National Highways Programme Manager, added: "We have worked closely with Hampshire County Council to prepare for these works, and we’ll be working throughout the festive period to manage their impact.
“Traffic levels are much lower at this time of year, but there will inevitably be significant delays at peak times. Our advice is to plan your journeys carefully and, if at all possible, avoid the area."
Once complete, these extensive enhancements are expected to make significant contributions to the local economy while improving traffic flow for years to come.