Police, ambulance and fire service attended the crash, which happened on State Highway 8 on the outskirts of Alexandra, near the intersection of Aronui Rd, just before 7pm today.
Traffic was restricted to one lane for some time.
A St John spokesman said three patients were assessed and treated at the scene.
Two had minor injuries and one had moderate injuries. It is understood none required hospitalisation.
It is the second serious crash in Alexandra today.
An 86-year-old woman died after two vehciles collided at the intersection of Clutha and Ventry Sts in Alexandra earlier this afternoon.
The crash, between a Mini and a Nissan 4WD, happened at the intersection of Clutha and Ventry Sts, just before 12:50pm.
The woman was transported to Dunstan Hospital, but died there from her injuries.
