A truck driver who ran over a man after he was knocked on to a busy Queensland motorway says he had no chance of avoiding him.

Clinton Livingstone was behind the wheel of a 13.7-tonne garbage truck when Tamate Heke allegedly punched Shane Merrigan into his path on December 1, 2015.

While giving evidence at Mr Heke's Brisbane Supreme Court manslaughter trial, Mr Livingstone said he was driving about 90 km/h when he felt something under his tyres.

Mr Heke was driving home from a 12-hour shift when he was tailgated and challenged to pull over on the afternoon of December 1, 2015, the Brisbane Supreme Court was told on Monday.

During the trial's opening, the jury was shown CCTV of the alleged attack in which Mr Heke and Shane Merrigan argue after stopping their cars near an exit on the Gateway Motorway.