A police spokeswoman said they were called to the crash at 10.50am.
A woman was trapped in the car for a time, the spokeswoman said.
A St John spokesman said one person was transported to Southland Hospital by ambulance with serious injuries.
A reporter at the scene witnessed the woman being removed from the car and taken to a St John ambulance on a stretcher.
She was conscious, but appeared distressed.
The car she was in was hit on the passenger side and significantly damaged.
Police said the road was blocked after the crash.