The M40 close to the Northamptonshire border has been closed after a crash involving more than 40 vehicles left one person dead.
The accident happened just before 8am on Saturday with drivers reporting thick fog in the area. Six people were seriously injured and between 35 and 45 people had minor injuries, according to Thames Valley Police.
The motorway was closed northbound between junction 9 at Bicester and junction 10 at Cherwell Valley services. It is expected to remain closed throughout the day.
Inspector Daren Courtenay, from the Joint Operations Unit for Roads Policing at Thames Valley Police, said: “Officers are currently on the scene attending the ongoing incident.
“The northbound carriageway is currently closed and is expected to remain closed for a number of hours. The southbound carriageway is open however restrictions are in place so delays should be expected.