When Oamaru man Stephen Carter saw a vehicle on a collision course with his, while travelling from Christchurch to Oamaru on Monday, he could scarcely believe what he was seeing.
The remarkable incident, captured on video via dashcam, unfolded shortly before 4pm on Monday, near Rakaia, when Mr Carter, a colleague and the latter's son were driving home to Oamaru in a Fastway courier van.
The footage shows a blue Ford Falcon, travelling at an unknown speed, pull out from the northbound lane of the highway while attempting to pass a car and a truck, heading straight for the van being driven by Mr Carter's colleague.
When the Ford driver apparently realised he would not be able to complete the overtaking manoeuvre, he steered on to the shoulder of the southbound lane.
If it was not for his cool head, Mr Carter said things might have turned out a lot differently.
''It was basically along the lines of 'what the ... is this ... idiot doing?' There's no way he's going to get through there'.
''All in all, it was pretty uneventful, but it could have been the opposite.
''It could have been catastrophic ... we just couldn't believe it.''
Mr Carter reported the incident to Oamaru police, who were investigating.
He said he had since learned the driver of the truck, who had also informed police, was a former police officer.
