"Cars now have higher boot lids, smaller rear windows and larger pillars both for design reasons and to protect those in the car," McDonald said.
"There are also spoilers for aerodynamics and higher rear headrests for safety - but this means visibility is hugely reduced."
McDonald's team found rear window visibility was worse in newer models but many were factory fitted with reversing cameras.
American researchers also highlighted the benefits of backing cameras.
Researchers from American company Insurance Institute for Highway Safety found factory installed cameras reduced blindspots by 90 per cent - and found some smaller cars, previously perceived to be safer, had blindspots as large as pickup trucks.
New Zealand experts looking into driveway deaths believe reversing cameras are a helpful tool but would not prevent them.
Clinical director at Starship Hospital Mike Shepherd said people should concentrate on "keeping driveways and kids separate" through good design.
"Driveway deaths are a complex issue and preventing them needs a multi-prong approach," Shepherd said. "Cameras have some use but it is more important to keep kids off driveways and stop using them as play areas."
Shepherd said hundreds of children would be killed or seriously injured on driveways before camera technology was widespread enough to make a difference.
He said cameras were designed to detect static obstacles, such as powerpoles and fences, but children could move fast and without warning.
"A camera is not going to help with your reaction time if a child suddenly runs out," Shepherd said.
Child safety group Safekids Aotearoa agrees. Ann Weaver said the research is encouraging but cameras are not foolproof and should be be used with other checks and proper child supervision.
"While reversing cameras and similar technologies are useful tools, they can only ever be an aid, and should never replace the need for driver care and attention," she said.
"It is the driver's responsibility to always check the driveway is clear."
Mother backs safety
Heartbreaking memories flood back every time Valeria Tokoar hears of a child run over in a driveway.
A relative reversing out of the drive killed her son, Tyreese Mewburn, outside his Napier home four years ago. He was just 19 months old.
"Every year we celebrate his life with dinner on his birthday," Tokoar said.
"Last year was hard because he would have turned 5, he would have been at school with his big brother Ashton."
Photos of the blond, blue-eyed boy adorn the walls of Tokoar's new home in Onehunga, Auckland. She has separated from Tyreese's father, Rocky Mewburn, but the pair keep their son's memory alive.
The grieving mother is backing our campaign to reduce driveway deaths.
The car that struck Tyreese was a Ford Falcon. Tokoar said knowing where children were at all times and parent supervision was key. "I have also heard reversing cameras are good."
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