Two people died when a vehicle transporter crossed the central reservation into oncoming traffic on the M1 on Monday.
The blue transporter travelling north crossed the carriageways between junction 14 and 15 near Northampton at about 14:50 BST.
Police said a woman and man in a car on the opposite carriageway which was hit by the transporter died at the scene.
Several other people were injured following the incident.
Northamptonshire Police said the transporter overturned onto the car containing the woman and man.
The M1 reopened at about 04:50 BST on Tuesday after the carriageway was cleared and central reservation had been repaired.