The study found hospitalisations of child motor vehicle passengers under the age of 16 for injuries sustained in a car crash showed no significant decline between 1998 and 2005.
Mr Wei Du, from the NSW Injury Risk Management Research Centre at The University of New South Wales, and his co-authors say that only hospitalisation rates for traumatic brain injuries had decreased significantly.
"Children with less serious injuries comprised the largest group, and their hospitalisation rate showed a non-significant increase over time," Mr Du says.
"In contrast, the hospitalisation rate for children with serious injuries or injuries of possible high severity ... had a steady but non-significant decline over time."
Mr Du says serious non-fatal injuries can lead to long-term disabilities and a burden on health care systems.
"Injuries to child motor vehicle passengers in NSW result in many hospitalisations each year and remain a significant public health issue."
Mr Du recommends further research into the suboptimal use of child restraint systems, such as premature graduation to standard adult seatbelts for young child passengers, and further efforts to reduce child road trauma.
The Medical Journal of Australia is a publication of the Australian Medical Association.