Police have named the two men who were killed in a Boxing Day car crash on the Waimate Highway north of Glenavy.
They were 80-year-old Horton James Hill of Christchurch and 31-year-old Matthew James Gilchrist of Oamaru.
On the day of the crash, Mid-South Canterbury area commander, Inspector Dave Gaskin, said a vehicle heading north was going too fast and crossed the centre line as it went around a bend.
He said it appeared the driver wasn't wearing his seat belt when he hit another car travelling south head on - and the impact of the crash tore one of the vehicles in half.
Mr Gaskin said he doesn't want the toll to rise any higher. "Please slow down, that's probably the best idea," he said.
"Everyone wants to have a really good long holiday, what we want is for them to get on holiday, enjoy themselves and then to come home and spend the rest of their lives with their loved ones."
Mr Gaskin said even when a collision doesn't end in a fatality, it still leaves a significant impact on people.
He said many of these crashes are preventable and he's urging people to stop being careless on the road.
The Serious Crash Unit and Waimate Police are investigating the circumstances surrounding the crash.