Police in Canterbury have found more than half the vehicles stopped in the region during a month-long operation did not have properly-installed child restraints.
Four hundred vehicles were checked, with 250 restraints found either not to be installed correctly, or not up to standard.
In some cases children were using adult seatbelts and not height appropriate restraints.
Senior Sergeant Rob Patterson said 224 of the 250 restraints identified as having issues were corrected by either the Police or Plunket technicians on the spot.
He said the drivers of the vehicles where restraints could not be corrected immediately were offered time to fix the problem, or face a $150 fine.