The M4 has been closed in both directions in Berkshire following a crash, with police warning that the westbound carriageway is likely to remain shut for several hours.
Thames Valley Police said the collision happened on the motorway between junctions 8/9 and 10, with emergency services attending the scene.
The westbound carriageway, carrying traffic from London towards Reading, is closed between junctions 8/9 and 10 and is expected to remain shut for several hours.
The eastbound carriageway, between junctions 8/9 and 10, is also closed, although police said it was likely to reopen later on Thursday morning.
In its latest update, Thames Valley Police said: “The M4 Eastbound is likely to reopen shortly but the Westbound will still be shut until at least lunchtime.”
The force is carrying out an investigation into the collision and said it hoped to provide a further update later on Thursday.
Drivers have been urged to avoid the area and seek alternative routes.
The closures are expected to cause disruption for motorists travelling between Reading and Maidenhead.
