Six people were injured in the nose-to-tail crash, which happened between Windermere and Swamp Rds near Hinds about 3.20pm last Thursday.
The vehicles involved included a van, two utes, and three cars.
Ashburton Volunteer Fire Brigade firefighters used cutting equipment to free the driver of the van.
They were assisted by Hinds firefighters at the scene.
Hato Hone St John responded to the accident with three helicopters, two ambulances, one first response unit, one operations manager, and one rapid response unit.
They said three people were transported to Christchurch hospital by helicopter, one in a critical condition, one in a serious condition and another in a moderate condition.
Another two people were transported to Ashburton Hospital by ambulance, one in a moderate condition, the other minor.
One patient with a minor condition did not require transportation to hospital.
Police said inquiries into the accident, which happened on a straight piece of highway, were ongoing.
‘‘There were roadworks in the area at the time of the crash,’’ police said.
‘‘The Serious Crash Unit attended and conducted a scene examination.
‘‘The scene was cleared at around 8.50pm.’’
Meanwhile, police received a report of a three-vehicle crash on State Highway 1, near Ealing, at about 11.20am on Saturday.
Police said five people received injuries, with one person receiving serious injuries.
‘‘The road was slightly blocked while emergency services were in the area.
‘‘Police are making inquiries into the crash.’’
