"The first couple of weeks of the school year are always a busy time on the roads," Mr Campion said.
Parents were trying to get back into a routine picking up and dropping off their children. They were also competing with the added congestion of other vehicles and children walking or biking to school, he said.
"Everyone needs to do their bit and keep their speeds down while driving past schools.
"Drivers need to make sure that children are restrained correctly and those who are dropping their children off need to park legally and considerately and be sensible to reduce the risk."
Mr Campion said that in past back-to-school police operations, the majority of motorists had kept to the speed limits outside schools, but there was still a minority who ignored restrictions.
"Kids are unpredictable at the best of times and when they return to school, they often want to catch up with friends who they haven't seen in a while and they can be distracted or unfamiliar with the area, so it's really important motorists take it easy and cut their speed right back."
Mr Campion said motorists also needed to be aware of 5-year-olds who were heading to school for the first time.
Plunket's national child safety adviser, Sue Campbell, said keeping children safe in vehicles was just as important as enforcing safety as they walked to and from school.
"Remember that no matter how short the journey, your child still needs to be restrained in a car seat or booster seat. Children are still way too small [at 5] to fit the vehicle safety belt on its own," she said.
A booster seat provided the best protection for young school children as it raised them up to window level and improved the fit of the safety belt, she said.
