Shaun Crosswell jogged beside a moving truck whose driver had passed out behind the wheel and reached into the cab to apply the brakes.
Mr Crosswell is one of two men whose quick thinking and bravery police say prevented a potential tragedy, when an out-of-control 29-tonne truck drove some 8km down State Highway 1 between Auckland and Hamilton last Friday.
Huntly West School principal Banapa Avatea drove directly behind the truck to stop other traffic passing after he saw it driving erratically and crashing into barriers near Hampton Downs.
He followed it for about 8km while on the phone to a 111 dispatcher until the truck crashed hard into roadside barrier, causing it to slow significantly.
He and Mr Crosswell, who was about three cars back in the traffic queue, chased it down the road on foot to try to stop it.