Christchurch police asked their Timaru colleagues to keep a lookout for the distinctive lorry, with an underage driver peering over the steering wheel. The message was also sent out to other truckies.
Confident of his driving abilities, after washing trucks at the Christchurch yard where his dad works, the boy drove down State Highway One, stopping at Ashburton for fuel, before again hitting the road.
He visited his mother in Timaru, before going further south to see his grandparents in Makikihi, Brent Rissman, Senior Constable of Timaru's Strategic Traffic Unit, said today.
When the youngster came back into Timaru at around 6.30pm yesterday evening, a police patrol car spotted him driving north on King St and pulled him over.
"Both boys were interviewed and they admitted their offending. At this stage, the file is being dealt with by Youth Aid,'' Mr Rissman said.
"The driver was reasonably blase about the whole thing, believe it or not. He didn't really think he'd done anything wrong but it's probably fair to say that he's not in his dad's good books.''
Police were stunned that the boy managed to drive so far in such a modern, complex machine.
There were no reports of accidents, or damage to the truck, which was returned to the boy's father.
"This young fella actually did quite a good (driving) job, but the potential for danger was extremely high.''
Police said the boy used the company's fuel card to fill up in Ashburton, and was wearing a "proper'' company shirt, which may have accounted for his ability to get served by unquestioning service station staff.
Mr Rissman was unsure if charges would be laid, saying it was in the hands of Youth Aid.
But the boy could, in theory he said, be charged with unlawfully taking a motor vehicle, burglary and using a document for pecuniary advantage, namely the fuel card. The passenger, also a 14-year-old from Christchurch, could be charged with unlawfully getting into a motor vehicle.
In March, a pyjama-clad 8-year-old boy was caught driving his parents' car in Wellington.
A TVNZ reporter followed the car after spotting it driving erratically. The boy pulled into a car parking building and clipped several other cars before emerging in tears.