The M27 between Junctions 9 and 11 will reopen a day early at 4am on Saturday, January 3, after major engineering works were completed ahead of schedule.

The motorway has been closed since Christmas Eve to allow the construction of improvements at Junction 10 using an innovative “box slide” technique deployed only a handful of times in the UK.

The project has been delivered by Hampshire County Council and main contractor VolkerFitzpatrick, in collaboration with National Highways, supported by specialist subcontractors.

Using precision engineering, a 60-metre-long pre-constructed concrete underpass was slid 65 metres into position before the road surface was reinstated.

The time-saving approach replaced what would otherwise have been many months of lane and speed restrictions, as well as overnight works, enabling the motorway to reopen earlier than originally planned.

During the closure, about 130 people worked a total of around 10,000 hours, around the clock. The M27 had originally been scheduled to reopen at 4am on Sunday, January 4.

Cllr Lulu Bowerman, Hampshire County Council’s cabinet member for highways, said: “This has been a mammoth engineering challenge, delivered by a dedicated team working around the clock right through the Christmas period.

“The complexity of the operation cannot be overstated – from excavating huge volumes of material to sliding an 8,500-tonne structure into place and rebuilding the road above it.

“We recognise the inconvenience this has caused for drivers and local residents, and I want to thank everyone for their patience.

“Thanks to the skill of our teams – and favourable weather conditions – construction has progressed smoothly, meaning we can now confirm the motorway will reopen a full day ahead of schedule.”

She paid tribute to the county council team and the contractors.

“Finishing this phase of the project paves the way for a new, free-flowing, all-moves junction due to open later this year, supporting the delivery of the Welborne Garden Village development,” she said.

“This showcases what can be achieved when the county council works closely with its public and private partners on a project of this scale, demonstrating our ability to deliver the infrastructure that underpins sustainable economic growth in Hampshire.”

The £100 million scheme is being delivered by Hampshire County Council, working closely with National Highways. It is fully funded by the Buckland Group, the developer of Welborne Garden Village, and Homes England.

The new underpass will connect Fareham with the Welborne Garden Village development, improving access to the M27 and supporting future growth in the area.

Andrew Jackson, National Highways programme leader, said: “I would like to thank all drivers and the local community for their patience and understanding while these improvements have been carried out.

“This has been a very complex operation requiring intense planning, teamwork and close collaboration with Hampshire County Council, VolkerFitzpatrick and their construction workers. We are delighted to be able to reopen the M27 earlier than planned and are thankful to all those who worked through Christmas to make this scheme a success.”

Adrian Mawdsley, VolkerFitzpatrick project director, added: “This is an incredible achievement from our team who have worked around the clock to ensure that the works have been delivered safely and to a high-quality standard.

“The many months of meticulous planning and contingency measures that have been put in place have meant we are able to open the motorway earlier than expected.”

Once the motorway reopens on January 3, lane restrictions and a 50mph speed limit that were in place before the full closure will remain. The safety measures are in place to protect drivers and crews completing the remaining work.

When open to traffic later in 2026, the underpass will provide two northbound and two southbound lanes connecting with new entry and exit slip roads at Junction 10. It will also accommodate a shared footway and cycleway connecting Fareham Common to the south and the Welborne Garden Village development to the north.

The two-year construction scheme is due to be fully open to traffic in winter 2026.