Only one of 22 children's car seats tested in NSW's Crashlab provided a child with maximum five-star protection against traumatic injuries to the head, neck and torso in a head-on collision at nearly 60km/h.
The Nuna Klik (rear-facing) child car seat was the only restraint to score five stars for the protection it provided in frontal, side and oblique crash tests at speeds ranging from 56km/h to 32km/h.
At the higher speed, the crash tests applied the same amount of energy that would be experienced in a fall from a five-storey building to test the degree to which a restraint protects a child.
Only four car seats got four stars for protection, under a new, more accurate and tougher star ratings system introduced in this year's testing at the NSW government's Crashlab. The five stars measure by how much the car seats exceed the national safety standard.
Six car seats, ranging in price, scored only one star. They included the $399 Maxi-Cosi Luna forward-facing seat, the Infa-Secure Kompressor 4 rear-facing child seat, and the $169 Babylove Cosmic 11 forward-facing seat.
When it came to ease of use, which can determine if a seat is installed correctly, the results were worse.
Not one of the 22 seats ( representing 13 different models) scored five stars. Most scored two stars. The only one to score four stars for ease of use was the Safe-N-Sound kid guard pro booster seat for children up to 10 years of age, which also got four stars for protection.
The NSW Minister for Roads Melinda Pavey said there was a "vast difference in the quality of protection [child car seats] provided", and it was important for consumers to know how they rate when they are put to the test.
Every seat on the market met Australia's high standards, Mrs Pavey said. "If they were unsafe, we would call it out, but some prove to be better than others."
Although most parents are using the right seat for their child these days, the majority of parents have trouble ensuring the seat is installed correctly.
At least 90 per cent of parents made mistakes, found a study by Neuroscience Research Australia (NeuRA), which watched as parents read manuals and then attempted to correctly fit and install a child-sized mannequin in a rear-facing restraint.
Bernard Carlon, executive director of the NSW Centre for Road Safety, said there had been a significant reduction in fatalities and injuries for children. "Most of that increase has come from the safety and security of child car seats," he said. "When you go back 20 years, the bassinet was thrown in the back seat."
In 1996, 59 children under 16 died on NSW roads. In the past few years, that number has dropped to fewer than 20. Not one young person that age has died so far on NSW roads this year.
The Crashlab experts also evaluated the instructions and assessed whether the seats were easy to secure and release.
For many parents and grandchildren, car seats are difficult to use. "It is a struggle," said Robin Dinh, of Cherrybrook, who frequently babysits her granddaughter Audrey, 22 months old. "It is hard to see in the car to do the belt up, hard to put the baby in without bumping her head [and mine] on the way, and you can't see where you are putting her."
Mrs Pavey acknowledged that a big challenge was to ensure the restraint was installed properly.
"You might have the best restraint there is, but if it is not put in properly it is not going to provide protection the child needs," she said.
The new child car seat ratings were updated to reflect the most recent Australian Safety Standard. They also used newer types of seats, such as those catering to older children, and used more realistically sized dummies of children and babies than in the past.
The NRMA's road safety expert Dimitra Vlahomitros said the ratings should encourage manufacturers to work on raising the safety rating and ease of use ratings to five stars. The road safety group provides assistance with installation of child restraints.
The results were released by the NSW Centre for Road Safety as part of the annual child restraint evaluation (CREP) program. It is a partnership between Transport for NSW, the National Roads & Motorists' Association, Royal Automobile Club of Victoria, Transport Accident Commission.