Police and Hall's are investigating after a truckie was captured cutting off a motorist on video.
In the video, a Hall's truck can be seen passing in front of the motorist, who is in the left-hand lane on State Highway 1 just north of Rakaia.
The truck appears to be so close to the motorist they are forced to drive off the road on to the grass verge.
Hall's chief operating officer Russell Hickin said they will conduct an internal investigation into the incident.
"Preliminary review of data for the vehicle involved has identified that the driver was not speeding over the limit at the time but video which has been provided by the complainant will be helpful as our internal investigation continues."
He said there is never any excuse for unsafe or discourteous driving on the road and no unsafe driving is considered acceptable.
"99.9 per cent of our drivers understand what good driving is. The majority are experienced, professional and take great care to abide by the requirements of what can be a very challenging role."
He said the Rakaia incident has led to a number of complaints and comments on social media and directly to the business which is disappointing for all those at Hall's who work very hard to promote a safe driving culture.
Operational managers across the company will be reminding drivers of what's expected of them, Hickin said.
"Once investigations are complete and appropriate action taken, a refreshed safe driving campaign will be run.
"While police are investigating there will be no further comment from the company on this incident."
The motorist, who the Herald has decided not to name, said he is pleased Hall's is working through the incident.
"I don't think that Hall's should be judged by one bad driver."
In a post to Facebook with the video, the motorist said the truck had initially been travelling closely behind him for some time.
"I did tap my brake lights to get him to back off. He never pulled back except to shine his high beams at me for well over a kilometre.
"He deliberately ran me off the road. You can easily see his wing mirror in the video, so he could clearly see me."