Children as old as five should be in rear-facing car seats according to an international road safety expert.
Thomas Carlson, who spearheaded the Swedish road safety policy that dramatically reduced the country's accident fatalities, said new information about the strength of car bodies made it unsafe for children under five toface forward in their car seats.
"We have known for quite a long time that children had to be three years of age but the structures of cars are stiffer now to protect passengers on impact," he said.
"Kids are not strong enough to handle the force. They break their neck because their muscles are not developed properly."
Mr Carlson, speaking at the Local Authority Traffic Institute conference in Napier, said it was time for manufacturers to develop vehicles that "assume responsibility for everyone in the car, including children".
Many vehicles were not suitable for installing rearward-facing seats and air-bags could cause serious harm to young children.
"Surely it must be in the manufacturers' interests to keep the prospective customer alive, "he said.
Mr Carlson said other countries could also follow the Swedish practice of reducing the speed limit to 30km/h outside schools and changing the road design in these areas to enforce that speed.
