Mr Semenoff said when his drivers were involved in accidents the first step was to make sure they were not hurt.
He said drivers who were not injured were made to go through an induction course, a driver training course which all drivers did when they start, before they got back on the road.
He said the driver from yesterday's crash, who was uninjured, would go through the course.
Mr Semenoff said the training process had been in place for about 46 years, since he had been in the transport industry.
"He's [the driver] very lucky," said Mr Semenoff. "We tell our drivers we don't own the road, we share it."
Lee Vickers, vehicle safety officer for the police commercial vehicle investigation unit, said the truck-and-trailer unit failed to make a corner half way between Dargaville and Poutu about 12.15pm yesterday and rolled into a drain.
It was the second time in about two years a truck had rolled over in the same spot.
Mr Vickers said the camber in the road was "not ideal" for drivers travelling towards Dargaville as it was quite flat.
Mr Semenoff said the truck-and-trailer unit would stay where it was overnight. He told the Northern Advocate yesterday that a team would be sitting down and working out a plan to remove the truck today.
In May the Road Transport Forum hosted the Rollover Prevention Programme series in Whangarei to prevent truck rollovers after a series of crashes involving logging trucks in Northland.