The M40 remains closed southbound between Junctions 10 and 9 following a fatal collision this morning.
The collision, between a goods vehicle and two cars, happened at about 10.50am.
A woman in one of the cars died from injuries she suffered in the collision.
The vehicles remain at the scene and the motorway will stay closed between Junctions 10 and 9 until at least 4pm to allow Thames Valley Police officers to conclude their investigations.
The Highways Agency has put in place diversions at Junction 10 and drivers are being urged to follow the motorway diversion symbols on signs, which will enable them to rejoin the motorway at Junction 9.