Emergency services were called to the crash at the intersection of Brougham (State Highway 76) and Selwyn Sts in Addington just before 11am on Monday.
Hato Hone St John said one person was transported to hospital in a serious condition.
The eastbound lane of SH76 was closed while the crash scene was cleared. It was reopened about 12.30pm.
The driver of the car was understood to have been trapped in the vehicle after the crash.
The person was treated at the scene and taken to hospital by ambulance.