Drivers across Hampshire face a weekend of motorway gridlock as National Highways enforces overnight closures on the M3 and M27 starting Friday at 9 p.m. The works, spanning maintenance, resurfacing, and electrical upgrades, will stretch into early mornings, forcing major diversions and lane restrictions at critical junctions.
On the M3, northbound traffic will encounter a full exit slip closure at Junction 6 from Friday through Sunday nights, with the adjacent roundabout partially closed in both directions. The Black Dam link road connecting to the A30 will also be shut during these hours, cutting off a key route for drivers heading toward Southampton.
Key Points
- ✅ M3 Junction 6 exit slip closed nightly from 9 p.m. to 6 a.m. Friday–Sunday
- ⚡ Black Dam link road shut during same window, affecting A30 access
- 💡 Roundabout partial closures at Junction 6 in both directions
The M27 will see even broader disruptions, with eastbound carriageway closures between Junctions 4 and 7 scheduled for Saturday night. Electrical works at Junction 3 will restrict entry and exit points in multiple directions, while Hampshire County Council crews target Junction 10 for overnight slip road closures on both sides of the motorway.
| Motorway | Junction | Closure Type | Works Type |
|---|---|---|---|
| M3 | 6 | Exit slip + roundabout partial | Resurfacing + Black Dam closure |
| M27 | 3 | Partial roundabout | Electrical |
| M27 | 4–7 | Carriageway | Major resurfacing |
| M27 | 10 | Entry/exit slip | Hampshire County Council |
Early travellers on Saturday face the heaviest hit, with the M27 eastbound carriageway between Junctions 4 and 7 shut entirely from 9 p.m. to 6 a.m., creating a 30-mile detour via the A3(M) and M271. Weekend holidaymakers heading to Portsmouth or the New Forest should plan alternative routes immediately, as National Highways warns of delays extending up to an hour beyond closure times.
💡 Pro Tip
Use live traffic apps like Waze or Google Maps before leaving—National Highways updates divert routes hourly. Avoid Junction 6 on the M3 entirely Friday and Saturday nights; the Black Dam closure adds 20 minutes to even the shortest trips.
Sunday brings no reprieve, with the M27 westbound between Junctions 3 and 2 shut for survey works during the same overnight window. Meanwhile, the M3’s Junction 6 remains a bottleneck, with resurfacing work extending into Monday morning. Commuters relying on these routes for work should consider public transport or flexible start times to dodge the worst delays.
📋 By The Numbers
- 3 nights — Closures active Friday through Monday
- 6 key closures — Affecting M3 and M27 simultaneously
- 30-mile detour — Standard for M27 eastbound carriageway closure
National Highways has deployed additional signage and digital alerts, but motorists are urged to check routes the night before travel. With no overnight exceptions, even late-night deliveries and emergency services could face rerouting. The closures mark the latest in a series of infrastructure upgrades across southern England, aimed at addressing aging pavement and outdated electrical systems.
- Plan ahead — Map alternative routes using A3(M) or A34 as primary detours
- Check time windows — Closures run 9 p.m. to 6 a.m., but delays may linger
- Use real-time tools — National Highways’ traffic cameras and Google Maps’ incident layer will show live closures
- Consider public transport — South Western Railway and local bus services offer viable alternatives for key routes
- Report issues — Delays or missing signage can be flagged via National Highways’ hotline: 0300 123 5000
The closures coincide with the start of the Bank Holiday travel season, amplifying the impact on holidaymakers and logistics networks. While the works are necessary for long-term road safety, the weekend timing ensures maximum disruption. Drivers are advised to factor in at least 45 extra minutes for journeys involving the affected sections.
- 📊 M27 eastbound closures will create the longest delays, with detours adding 45–60 minutes to trips
- 🔍 Junction 10 works on the M27 are part of a larger Hampshire County Council initiative to upgrade local access roads
- ⚠️ Black Dam closure on the M3 cuts off a direct A30 link, forcing detours through Winchester
National Highways has confirmed that all closures are weather-dependent and could be extended in heavy rain. Crews will prioritize reopening slip roads before full motorway lanes to ease traffic flow. Motorists caught in unscheduled closures are advised to follow diversion signs and avoid stopping on hard shoulders.