A truck driver was taken to Timaru Hospital in moderate condition after a trailer rolled near Twizel this morning.
A Fire and Emergency New Zealand spokeswoman said the road between Twizel and Omarama was blocked after the crash which happened about 4.20am.
A truck and trailer had rolled, blocking the road.
The driver, who was the sole occupant, did not require extrication.
Two crews, from Twizel and Omarama assisted at the scene and the road was cleared about 7am, she said.
A St John spokeswoman said a first response unit, an ambulance and a primary response doctor attended the scene near Glenbrook.
One patient was transported to Timaru Hospital in a moderate condition, she said.