A man has been arrested on suspicion of causing death by careless driving after a motorcyclist died in a rush hour crash.
The victim, aged 53 from Slough, died at the scene on the eastbound M4 near junction 11 in Reading on Friday at about 17:00 BST.
Police are quizzing another man, aged 33 and from Cardiff, on suspicion of causing death by careless driving.
The motorcyclist collided with two cars on the motorway.
The eastbound carriageway was closed for four hours while investigation work took place, causing long delays.
The drivers of the cars were uninjured.