One person died when a car and truck collided in Clandeboye, north of Timaru, on Sunday morning.
The accident happened on Canal Rd just before 1am.
One died at the scene, and two others were taken to Timaru Hospital.
The serious crash unit and commercial vehicle safety team are investigating.
The road toll for 2018 stands at 97, 11 deaths more than at the same time last year.