Another truck driver also noticed the manner of the truck's driving and alerted authorities, too.
The truck finally came to a halt after being pulled over by police responding from Matamata.
Mr van de Wetering wouldn't elaborate on what the offending truck driver told police in his explanation for his actions, but says his response would be taken into account during their investigation.
The driver had been subsequently stood down from driving for a period of time, he says.
"The point that I make here is that we are impressed and thankful that members of the public really made efforts to alert us in the first instance ... road safety is everyone's responsibility. In this case here, it was a successful response by members of the public -- they didn't ignore what was a potentially dangerous situation."