Another large Summerland Express Freight truck has crashed, this time on State Highway 1 south of Ashburton.
It is the third crash involving one of the transport company's vehicles in three weeks.
A Fire and Emergency New Zealand spokesman said the truck and trailer unit rolled about 4.40am, blocking SH1 for several hours.
The highway between Ashburton and Rangitata was closed and traffic was diverted.
No-one was hurt and the driver was out of the overturned cab by the time fire crews arrived.