A motorist travelling close to a truck and trailer which tipped over on the Whangamoa Saddle said it was lucky it fell into the opposite lane "otherwise he might have killed me".
The truck tipped over on State Highway 6 as it travelled from Nelson towards Blenheim just before 11.30am.
Gold miner Ron Clark, who was driving towards Nelson when the crash happened, said fortunately the truck toppled towards the roadside bank.
The truck cab was hard up against the bank and on its side, and the trailer partly over, he said. The driver did not appear to be injured.
The crash meant traffic stopped suddenly and caused two minor nose to tail accidents on both lanes, he said.
While the truck was not blocking traffic a crane would be needed to right the truck.