"We were surprised to discover that the injury rate was considerably lower in crashes where grandparents were the drivers," said Dr. Fred Henretig, an emergency medicine specialist at Children's Hospital of Philadelphia and the study's lead author.
Previous evidence indicates that car crashes are more common in older drivers, mostly those beyond age 65. The study looked at injuries rather than who had more crashes, and found that children's risk for injury was 50 percent lower when riding with grandparents than with parents.
The results are from an analysis of State Farm insurance claims for 2003-07 car crashes in 15 states, and interviews with the drivers. The data involved nearly 12,000 children up to age 15.
Henretig, 64, said the study was prompted by his own experiences when his first grandchild was born three years ago.