A New Zealand man who punched a motorist who fell in into the path of an oncoming garbage truck on the Gateway Motorway has been sentenced to six-and-a-half years in prison.

Tamate Heke was acquitted of manslaughter, but was found guilty of unlawful striking causing death by a Supreme Court jury in Brisbane yesterday.

Shane Merrigan, 50, was killed when he fell under the wheels of a garbage truck during the road rage incident in December 2015.

Heke was ordered to serve a minimum 80 per cent of his sentence behind bars before being eligible for parole, meaning he must serve at least five years and two months.

Justice Peter Applegarth told Heke that when he was confronted by Mr Merrigan he should have got back in his car.

"You should not have let your anger get the better of you," he said.

Shane Merrigan died after being hit in a road rage incident on a motorway in 2015. ( ABC News )

At Friday's sentencing hearing in the Supreme Court in Brisbane, defence barrister Joshua Fenton said Heke was "a hard-working family man".

He said after the unlawful striking occurred, Heke saw a psychologist for anger management, who found he was developing depression as a result of incident.

Mr Fenton told the court Heke cried and largely confessed at the scene, before admitting to the punch early on in the police interview.

"He made a mistake," Mr Fenton said.

"[It was] a two-second brain explosion with tragic consequences."

Prosecutor David Meredith said the whole incident "took about 30 seconds" from the men pulling over to the side of the road and when Mr Merrigan was struck by the truck.

"He [Heke] has not shown remorse," Mr Meredith told the court.

Mr Merrigan's daughter Megan fought back tears as she read a victim impact statement to Heke.

She said she found out her father was dead on Facebook, when she saw her sister's car in the news footage at the crime scene.

"I've suffered nightmares after nightmares almost every week since it's happened," she said.

"Every time I close my eyes I get visions of the scene.

"I'm scared to drive most days because the slightest bit of road rage causes me to panic.

"I'm scared of what could happen to me ... I don't want to end up like my dad."

Judge questions sentences

While the jury acquitted Heke of manslaughter he was found guilty of unlawful striking causing death, which was introduced after a series of fatal one-punch attacks in Queensland.

Justice Peter Applegarth said both charges carried a maximum penalty of life in prison, but Heke has to serve a minimum 80 per cent of his sentence behind bars under the unlawful striking laws.

"If you are acquitted of manslaughter but convicted of unlawful striking causing death you walk into an 80 per cent non-parole period," Justice Applegarth said.

"It begs the question as to why manslaughter is the first count and why unlawful striking causing death is the second charge.

"There's not a consistency of practice.

"The government and the legislators decide these things, it's just that when they do we're all given the task of working out the consequences."

Justice Applegarth said Heke "knew the risks" when he pleaded not guilty to manslaughter at the beginning of his trial.

"Perhaps in retrospect Mr Heke might today wish he had pleaded guilty to manslaughter, even though he was acquitted of that offence," Justice Applegarth said.