A truck has rolled blocking State Highway 1 in Canterbury.
The section of road, on the Waimate highway near Kingsbury Rd, was expected to remain closed for about two hours while the crash was cleared.
A Fire and Emergency NZ spokesman said a 22-wheel truck and trailer was involved.
The driver was currently trapped in the cab and firefighters were working to get him out.
Power lines had also been damaged and authorities had been notified. The spokesman confirmed the truck was not carrying any dangerous goods.
Police said they did not believe anyone had been injured in the crash, which took place about 2.30pm.
Northbound traffic was being diverted at McNamaras Rd, through Parsonage Rd, Waimate Hunter Rd, and Lower Hook Rd. Southbound traffic was being directed off SH1 at Lower Hook Rd.
Motorists were asked to take extra care while the diversions were in place and avoid the area if possible.