Sixteen vehicles collided in thick fog on the A303 near Thruxton on Saturday night, forcing an overnight shutdown of the westbound carriageway between Wiltshire and Hampshire while emergency crews triaged casualties and dealt with a large oil spill.

Hampshire Constabulary said the pileup happened shortly after 20:20 GMT on the westbound lanes close to Thruxton airfield, a stretch that carries weekend traffic between the South West and London. South Central Ambulance Service reported that about eight people sustained minor injuries and that one person with a suspected broken arm was taken to hospital by relatives rather than ambulance.

Response on a fog-bound carriageway

SCAS dispatched two ambulances, rapid-response cars with a specialist paramedic, a team leader and members of its Hazardous Area Response Team because of the scale and complexity of the scene. Police closed the road between junctions for Quarley and Weyhill, diverting drivers onto local routes while investigators documented vehicle positions.

National Highways said thick fog was present when officers arrived. The agency kept the westbound carriageway shut between the A342 near Thruxton and the A338 near Cholderton on Sunday morning while specialist cleaning crews removed fuel and lubricant spread across multiple lanes.

Cleaning crews and surface checks

By dawn on 8 November, recovery contractors had cleared the cars and lorries involved, but National Highways warned that the oil contamination required "extensive specialist cleaning" before traffic could safely resume. The agency said an inspection would be needed to determine whether the spill had damaged the road surface itself, a step that can add hours even after visible debris is gone.

Drivers posted social media warnings about long diversions through villages west of Andover. Rugby fans travelling between Exeter and London clubs and families returning from Dorset half-term breaks were among those caught in the backlog. Police urged anyone with dashcam footage to contact investigators, a standard request after multi-vehicle shunts where several drivers may be interviewed.

The Thruxton incident followed a separate dense-fog collision on the M20 in Kent on Saturday evening that seriously injured two people among more than 30 vehicles. While the two events are not linked, they underline a weekend weather pattern: clear, cold nights allowing valley fog to pool on fast trunk roads.

The Met Office had flagged patchy fog across southern England into Sunday morning. National Highways reiterated advice to use dipped headlights, increase following distances and avoid sudden lane changes when visibility drops below 100 metres.

What drivers face on Sunday

As of mid-morning on 8 November, National Highways had not confirmed a full reopening time, citing the combined cleaning and structural check. Once the westbound A303 reopens, eastbound delays may persist while contraflow recovery vehicles exit the scene.

For Hampshire and Wiltshire residents, the closure is more than a traffic inconvenience: Thruxton sits on a key military and motorsport corridor, and weekend closures ripple into Andover, Amesbury and Salisbury supply routes. Police said inquiries into the precise sequence of impacts remain active, with no charges announced in the first public updates.