So many child car restraints are wrongly installed because parents can't follow the instructions. And don't blame parents, those instruction manuals are just too hard to understand.

Julie Brown, senior research scientist at NeuRA, has been working hard to make children safer in cars for over 30 years but this time she feels that success is near.

"We found that parents really can't understand the instructions and this is linked to the types of errors they are making in using restraints," she says.

"But we've also identified a method for improving the way in which instructions are developed."

The secret? Real people.

Brown and her UNSW team, including Alexandra Hall, asked parents to read instructions and then install the seats. At first, the success rate was around 30 per cent.

Think about what that might mean for child safety. It means 70 per cent of children are travelling in seats which aren't doing what they are designed to do.

Then Brown, who presented at this week's Australasian Injury Prevention conference in Ballarat, used feedback from real people to make changes and they did that over and over again until almost all seats were correctly installed. Their pilot participants weren't all parents, they were diverse in terms of both their experience with children and their backgrounds.

"Each round of change led to increasingly positive feedback," says Brown.

Which is a relief. Brown's research over time showed restraints which had been fitted in the wrong direction or the straps had not been tightened sufficiently.

"In the field, we see anything you can imagine which could possibly go wrong actually going wrong."

But as the pilot study progressed and the clearness of instruction manual improved, there were fewer and fewer errors. By the time the pilot study was over, more than 80 per cent of child safety restraints were correctly installed by the participant.

It only took three years but now Brown and her team have a set of materials they know parents can understand. Now they are about to start a large randomised control trial and with any luck, the next round of instructions will be so accessible that maybe kids can install their own.

Cassidy Boyd and her partner Matt Button, of Turner, are the parents of Darcy Button, now nine days old. They decided to go straight to Kidsafe to get their capsule installed so they could be confident it was done correctly.

"We didn't want to struggle through the installation process when there are people who are experts," she says.

Boyd also said that the seat they had intended to use had a slightly frayed seatbelt and the installers at Kidsafe pointed out that it might prove a safety risk.

"We wouldn't have identified that ourselves and I doubt that would have been in the capsule manual."