M27 Junction 10 Underpass Opens Monday 14 September

The rebuilt M27 junction 10 starts opening to traffic today. Hampshire County Council says the first phase brings the new westbound off-slip road, the motorway underpass and four new roundabouts into use from 14 September 2026.

The new westbound off-slip takes traffic off the M27 coming from the Portsmouth direction and feeds it onto the new carriageway and through the underpass. It replaces the existing junction 10 westbound off-slip loop, the tight curve drivers have used for decades.

The new dual carriageway under the motorway is to be known as the A32/A3222 link road. It does not open in full. The council says it will initially operate with a single lane in one direction, northbound, giving a new route towards Fareham, Wickham and the local road network. That arrangement lets the remaining work, including landscaping and finishing the footways, be done safely.

What opens today, and what does not

Opening now:

• the new westbound off-slip from the M27
• the motorway underpass
• four new roundabouts
• the link road, northbound only, one lane

Still to come:

• the eastbound off-slip and the westbound on-slip, which the council expects in autumn 2026
• the full dual carriageway through the underpass

One thing drivers will notice straight away. Temporary speed limits and lane restrictions stay on the M27 between junction 9 at Whiteley and junction 11 at Fareham. The council says they remain while final safety checks, including technology testing, are completed, and expects them to be in place until winter 2026. Access to Dean Farm will be available at Welborne Approach Roundabout, both from the new westbound off-slip and from the A32 at Fareham and Wickham.

The paperwork that proves it

The announcement is not the only record. Hampshire County Council has also made three permanent traffic orders covering the new road, and they come into force today, Monday 14 September. The council made them on 1 September and advertised them on 11 September.

They apply to the A3222 Welborne Link Road, between its junction with the A32 Wickham Road and its roundabout junction with the M27 westbound slip road, including the circulatory carriageways of every roundabout in between:

• Order C896 sets a 40mph speed limit along that whole length.
• Order A2175 bans waiting at any time.
• Order A2176 prohibits entry from the link road onto the M27 westbound off-slip and onto the M27 eastbound off-slip.

That last one is worth reading twice. The new slip roads bring traffic off the motorway, and the order makes it a legal offence to drive up them the wrong way from the link road. It is the sort of restriction a junction only needs once it is carrying traffic.

Anyone who wants to challenge the orders in the High Court has until Friday 23 October 2026. The orders, the maps and the statement of reasons can be inspected at Fareham Library on Osborn Road, at the Civic Offices on Civic Way and at the county council’s headquarters in Winchester.

The closure that ended this morning

The junction 10 westbound off-slip was shut all weekend, from 9pm on Friday. National Highways’ closure report for 11 to 17 September gives its end as 6am on Monday 14 September, the same morning the new layout comes into use, and lists the work as being done for Hampshire County Council.

No further junction 10 closure appears anywhere in that report for the rest of the week. The only M27 entry left in it after today is at junction 4 near Chandler’s Ford, about ten miles north west of Fareham, closed eastbound between the slip roads from 9pm tonight to 6am on Tuesday.

Why the junction was rebuilt

Junction 10 has never been a full junction. The council’s scheme page says it allowed only partial movements, westbound off and eastbound on, which is why traffic between Fareham and the Southampton direction has had to use junction 9 or junction 11 instead.

The rebuild makes it an all-moves junction. The council puts the cost at more than £100m and gives the scheme a start of autumn 2024 and an end of winter 2026. Its stated purpose is blunt: the upgrades are needed “to help bring forward the development of Welborne Garden Village to the north of Fareham”. Welborne is the largest single source of new homes in the borough’s housing supply, and the numbers are on our Fareham planning news page.

The heaviest engineering was done in the 2025 Christmas period. A pre-built 60 metre concrete structure was moved 65 metres into position beneath the motorway using a box slide, then the road surface was reinstated. The council says the work finished ahead of programme and the full M27 closure was lifted a day earlier than planned.

The opening was marked by representatives of the organisations that built and funded the scheme: Buckland Group, Homes England, National Highways, VolkerFitzpatrick, and the county council’s leader Councillor Nick Adams-King and its cabinet lead for highways Councillor Steve Forster.

What it means for you

• If you come off the M27 westbound at junction 10, you are now using a new slip road. The old loop has been replaced.
• If you are heading for Wickham or the A32 north of Fareham, there is a new route through the underpass, but it is one lane and northbound only.
• There is still no eastbound off-slip and no westbound on-slip. For those moves you continue to use junction 9 or junction 11 until autumn 2026 at the earliest.
• The 40mph limit on the link road is now legally in force, as is the ban on waiting at any time.
• The temporary limits on the M27 between junctions 9 and 11 have not gone. The council expects them to stay until winter 2026.
• The council warns the programme can change for weather or operational reasons, so check before a late journey.

Live closures, the rail engineering work and the rest of the borough’s roads are on our Fareham roadworks and travel page, updated each week. Train times are on our Fareham trains to London page, and town centre tariffs are on our parking page.

Sources

• M27 Junction 10 reaches major milestone with phased opening from 14 September, Hampshire County Council, published 9 September 2026, for the phased opening, the westbound off-slip, the underpass, the four roundabouts, the single northbound lane, the Dean Farm access, the autumn 2026 slip roads, the winter 2026 restrictions, the box slide figures and the list of representatives.
• M27 Junction 10 improvement scheme, Hampshire County Council, for the cost, the autumn 2024 start, the winter 2026 end date and the description of the existing partial junction.
• The Hampshire (A3222, Welborne Link Road, Fareham) speed limit, prohibition of waiting and no entry orders 2026, public notice 23015, for the three orders, the 14 September date of operation, the 1 September making date, the extents, the inspection addresses and the 23 October High Court deadline.
• National Highways road closure report, the seven day report covering 11 to 17 September 2026, for the end of the junction 10 slip closure at 6am on 14 September and the junction 4 closure.