Emergency services have closed a stretch of motorway in Northamptonshire.
It comes after a collision that caused a vehicle to roll over on the M1 Southbound between Junction 16 A4500 (Daventry) to Junction 15A A5123 (Towcester / Northampton Services).
The accident has caused severe delays due to stationary traffic, the Highways Agency says.
A spokesman said: "Highways have closed the carriageway to assist with the accident. Emergency services at scene dealing with situation. Entry slip road closed also."
Diversions are via the A4500, A5076 and A5123.