A police spokesperson said the road was now closed and diversions were being put in place.
Motorists were asked to travel on the alternative route.
The serious crash unit had been advised and inquiries were under way into the circumstances of the crash.
In the second crash emergency services responded to a single motorbike accident on Christchurch Akaroa Rd near Bayleys Rd, Birdlings Flat.
The accident happened around 5pm, said a spokesperson.
“One person is in a critical condition and the Serious Crash Unit has been advised.
“The road is down to one lane while emergency services work at the scene, motorists are advised to expect delays.”