Weekend engineering work at the M3 Junction 9 roundabout is causing heavy traffic and disruption on routes into Winchester, with diversions funnelling vehicles through the city and neighbouring villages while slip roads remain closed.
Closures and diversions
National Highways has closed the Junction 9 roundabout and all its slip roads for the first of three planned weekend operations. The closure is in place from Friday and will remain until 06:00 on Monday 3 August. While the M3 main carriageway remains open through the junction, motorists cannot join or leave the motorway at J9.
- Traffic between Basingstoke and Winchester has built up, particularly on the stretch between Junction 7 (Basingstoke) and Junction 9 (Winchester).
- Diversions route drivers via Winchester city centre, Bar End, Chilcomb and surrounding villages.
- Some traffic on the A272 is being diverted north to Junction 7 to rejoin the motorway, adding load to that stretch of road.
What drivers should expect
Road users attempting to access the M3 at J9 are being asked to follow local diversion signs. The northbound entry slip at J9 has been closed on a longer-term basis since Friday and is not due to reopen until winter 2027, forcing northbound drivers who would normally use J9 to detour south to Junction 11 at Hockley Cross before rejoining the motorway.
National Highways has warned against relying on satnav for this diversion, as it may direct drivers onto closed or unsuitable roads.
Commuters and haulage operators should note that two additional full weekend roundabout closures are scheduled, creating a pattern of disruption through the autumn unless plans change:
| Closure dates | Impact |
|---|---|
| Current: until 06:00, Monday 3 August | Roundabout and all slip roads closed; mainline remains open |
| 21–24 August (weekend) | Full weekend roundabout closure |
| 11–14 September (weekend) | Full weekend roundabout closure |
Local consequences and commuter-belt tensions
For Winchester residents and those who commute across the M3, the closures are more than a short-term inconvenience. The diversionary routes pass through built-up urban streets and smaller rural lanes not designed for sustained high volumes of through traffic, increasing journey times and placing additional pressure on local junctions and parking areas.
Businesses that rely on punctual deliveries, school runs and morning and evening peak commuters will notice a change to travel patterns while the slip roads are unavailable. The decision to route some A272 traffic north to Junction 7 near Basingstoke will also redistribute congestion rather than eliminate it, raising the risk of delays spreading across a wider area.
Residents in Bar End and Chilcomb should expect more vehicles, including larger commercial vehicles, using their local roads as drivers follow signed diversions. Motorists are being urged to plan journeys in advance, allow extra time and follow the official diversion signs rather than depending on satellite navigation.
What to do if you must travel
- Allow additional journey time when travelling between Basingstoke and Winchester.
- Follow official diversion signage and traffic-management instructions.
- Avoid using satnav alone for routeing through the affected area during closures.
- Consider delaying non-essential journeys until after 06:00 on Monday if possible.
Further updates are expected from National Highways and local traffic monitoring services over the weekend. Motorists are advised to check live traffic reports before setting out and to heed warnings about unsuitable local roads being suggested by satnav systems.
