Punch turned roadside fight deadly: court

A New Zealand man dealt a heavy blow "out of nowhere" to the head of a driver in a fatal 13-second road rage incident on a busy Brisbane motorway, a court has heard.

Tamate Henry Heke allegedly struck Shane Merrigan, 50, forcing the local man into the path of an oncoming rubbish truck on the Gateway Motorway at Eight Mile Plains on December 1, 2015.

Graphic footage of the incident was played to the jury on the first day of Heke's trial at the Brisbane Supreme Court.

He has pleaded not guilty to one count of manslaughter, as well as not guilty to an alternative charge of unlawful striking causing death.

Crown prosecutor Clare Kelly said both men had been making their way home from work before pulling over to the left shoulder of the road and facing each other "for about 13 seconds".

The New Zealand national is accused of then delivering a "heavy blow" to Mr Merrigan's head, causing him to fall into the path of the truck, travelling at 90km/h.

Photographs showing the truck's blood-splattered undercarriage were on Monday viewed by jurors.

They also saw the graphic footage from a motorway camera showing the moment of impact, plus the lead-up events.

The rubbish truck driver, Clinton Livingstone, later told the court he saw the two men get out of their cars and approach each other with "their chests out".

"Then it looked like one punched the other one (and) I felt something under the truck" he said.

Mr Livingstone said he had sounded his horn shortly after spotting the stand-off because he didn't want either man to step back into his path.

Another witness, Louise Moss, said she saw a man punch the other "quite strongly".

She said the two didn't appear to be fighting before the blow and described it as coming "out of nowhere".

Under cross-examination, it was heard Ms Moss's initial police statement described seeing two males who looked as if they were fighting.

The court heard Heke told police Mr Merrigan had pushed him twice as well as taken a swing at the left side of his face.

He also told them he had tried to catch Mr Merrigan before he fell into the path of the truck, it was heard.

But Ms Kelly said there were "clear disparities" between this account and footage of the encounter.

Defence barrister Anthony Kimmins said Heke told police he didn't intend to get into a fight when he pulled over.

He said Mr Merrigan had been gesturing at Heke with his middle finger, with the accused allegedly telling investigators he thought the other man would "back off".

The court heard Heke told police the Logan resident was "coming at me pretty quick" during the encounter and claimed the late man said "c**** like you shouldn't be on the road".

The trial continues.