Constable Kieran Young responded to the reports of the man and went to see just what was going on.
"He said he has had enough of living rough in Christchurch and he is heading home to the far north," he said.
He was undeterred, Constable Young said, about the incoming weather bomb or the fact that it is a very long hike - in fact, he had packed provisions.
"He had a couple of blankets, a bag, a loaf of bread and two Kingfisher beers in the trolley and he is determined to get back north," he said.
Police tried to convince him it was not a good idea, but he was persistent, so they got him off the motorway and sent him north on a less busy road.
Constable Young said normally they would have given him a ride up the road to the next town, but his shopping trolley was too big to fit in the patrol car.