Two people have died in a crash near Christchurch, which closed several lanes of the city's northern motorway for almost five hours.
Police said the crash happened near Chaney's off ramp, shortly before 5.30pm.
It is understood a van travelling south, collided with a four wheel drive vehicle towing a trailer, which was also travelling south.
The four wheel drive left the road and hit a tree, killing both occupants.
The driver of the van was taken to Christchurch Hospital and is helping the police with their enquiries.
The deaths have been referred to the coroner.
It brings to 10 the number of road fatalities over the weekend.