Almost 7 per cent of children under 5 are not properly restrained in cars, a survey shows, and police say more could be done to ensure children are safe.
The Ministry of Transport survey found 93 per cent of children under 5 in cars were in an appropriate child restraint, an increase of 1 per cent from the last survey in 2012.
The rest, almost 7 per cent, were either improperly restrained or not strapped in at all. Three per cent were wearing adult safety belts and a further 3.2 per cent were completely unrestrained - including almost 1 per cent who were held on the knees of passengers.
The survey found more than half the children under 5 were in child seats and 20 per cent were in baby capsules or infant seats. A further 19 per cent were in booster seats and 0.8 per cent were in child harnesses.
The findings come after 5600 children in cars were observed at 112 locations in October last year.
Acting national road policing manager Inspector Peter McKennie said police wanted all children under the age of 7 to be in child restraints.
"If a child is unrestrained, we have to look at why this is. If it relates to cost and affordability, there is assistance available in many communities."
Mr McKennie said police would follow up on reports from members of the public of unrestrained children in vehicles.
"It may be with specific inquiries with the driver or vehicle owner, or it may be a letter to the owner in the case of a community Roadwatch complaint."
Plunket's national adviser for child safety, Sue Campbell, said the results of the survey were positive, but she wanted to ensure parents were using the right restraint and it was installed correctly.
"I think 93 per cent is a good figure in as much as it's the realisation that families are doing the best they can to restrain their child in vehicles."
She said the number was creeping up and it supported the idea that the message was getting through.
Ms Campbell said Plunket provided a community service to ensure children were in appropriate restraints for their size and they were installed correctly.
Land Transport safety manager Leo Mortimer said child restraints played a vital role in reducing the severity of crash injuries.
"Adult safety belts are designed for adults, and do not fit children correctly. Organisations such as Plunket are able to give parents and caregivers advice and support to make sure children are in an appropriate and correctly installed restraint."
Last year, the parents of a 12-week-old baby who died from injuries in car crash while allegedly unrestrained were charged with failing to provide the necessities to prevent injury.
Alexandria "Lexie" Grace Navacilla was one of six people in the car that crashed near Aria, in the Waikato, on May 19. She was allegedly being held on her mother's lap when the crash happened and police reported at the time that they found a car seat in the boot of the car.
The driver of the car was charged with careless driving causing death.
By the numbers
•93% of children under 5 in child restraint
•3% wearing adult safety belt
•1% held on adult's knee
Source: Ministry of Transport
•Children under 7 to be restrained in vehicles
•Keep babies and toddlers rear-facing in car seats until 2 years of age
•After 2, children should be restrained in a car seat until over recommended weight
•A booster seat is recommended until child is taller than 148cm