A man has died after his car crashed into the back of a lorry on the M1 near Milton Keynes.
Thames Valley Police said a silver Ford Fiesta hit an HGV between junctions 13 and 14 of the northbound carriageway at 22:45 GMT on Friday.
The driver of the car, a man in his 40s, was taken to hospital, where he died as a result of his injuries.
Pc Phil McGlue described it as "an extremely tragic incident" and appealed for witnesses to come forward.
He also urged drivers to check their dashcam footage.
No arrests have been made, police added.