A bad accident closed the M61 at Walton-le-Dale today after a car overturned.
The incident occurred at around 10am this morning, near to junction 9, Brindle, with the M65 also affected.
Just before 5pm this evening, police said the carriageway had been reopened and traffic has cleared.
One person has suffered serious injuries and has been taken to hospital and three others were hurt.
AA Roadwatch said: "Main roadway closed and queueing traffic due to accident on M61 Southbound at J9 J2 M65 (Clayton Brook).
"Congestion to M6 J31 (Samlesbury). All traffic was being temporarily held whilst cones were put out to close the lanes off. All emergency services are on scene. Air ambulance is on scene. Detour in operation - via exit and entry slip road."
Highways England said: "The M61 southbound is closed between the slip roads at J9 Brindle. Traffic is currently being held whilst our Traffic Officers manage the closure. Once released, traffic can exit the motorway at J9 and re-join at J9 entry slip, avoiding the incident.
"Please be patient if caught in the backlog of traffic."
The traffic is causing tailbacks on the M6 southbound at Ribbleton, Highways England said.
AA Roadwatch said the road was likely to be closed until late afternoon.
They reported: "Accident Investigation works are now underway following the earlier accident which resulted in an overturned vehicle. The road is likely to remain closed until late afternoon."