A GERMAN father abandoned his 14-year-old son on a highway 450 kilometres from home after an argument, saying he wanted to teach him a lesson.

The man from the Rhineland in western Germany threw his son out of the car at a rest stop in the southern state of Bavaria on Sunday during a cross-country drive, giving him €5 ($7.50) to make his own way home.

When motorists saw the teenager walking on the side of the road at dusk, they called the police.

Officers picked up the boy and called his father, who was already north of Frankfurt, about 130 kilometres away.

"The man said he wanted to teach his son a lesson," police said in a statement, adding that he recommended the child be kept for a night at the police station.

Officers finally convinced the man to return to collect his son in Bavaria.

"After father and son had hugged and promised each other to get along again, they started off together on the 400 kilometre journey home," the statement said.

Police informed child welfare authorities of the case.

