Police, Hato Hone St John and Fire and Emergency New Zealand responded to the crash at the intersection of State Highway 1 and Georgetown-Pukeuri Rd (SH 83) just after 2pm.
A police spokesperson said SH 1 was closed for about 20 minutes before reopening with one lane.
Both lanes were open again by 3.30pm.
A St John spokesperson said two people were injured. One had minor injuries while the other with moderate injuries was transported to Oamaru Hospital.