(Reuters) - Carrying a passenger younger than 21 increases the risk of a driver aged 16 or 17 dying in a car crash by 44 percent, a U.S. study showed on Tuesday, highlighting risks of young drivers chauffeuring their friends.
The study, by the American Automobile Association, said most U.S. states have passed laws in recent years limiting how many passengers young drivers can carry, and that the number of fatal crashes involving teen drivers has fallen as a result.
But the motor club said in its report that studies on the topic of teens driving with passengers were more than a decade old, so the organization sought to "provide updated estimates."
The report found that drivers aged 16 or 17 increase their risk of dying in a crash by 44 percent when they have one passenger younger than 21 in the car.
The fatality risk for a 16- or 17-year-old driver doubles when he or she is carrying two passengers younger than 21, and quadruples when three or more such passengers are present.
Teen drivers are more at risk with young passengers because they are likely to become distracted, the AAA has said.
Conversely, the study said, when a driver aged 16 or 17 carries a passenger who is 35 or older, the young motorist's risk of death is cut by 62 percent, suggesting the extra pair of eyes from an adult helps guard against collisions.
"We know that carrying young passengers is a huge risk, but it's also a preventable one," Peter Kissinger, president and chief executive officer of AAA Foundation for Traffic Safety, said in a statement.
He added that the study's findings should send a clear message to parents not to let their teens travel in a car with other young people.
Carol Ronis, a spokeswoman for the AAA Foundation, said the report did not include data on how or if carrying a passenger affected the risk of an adult drivers dying in a crash.
The study analyzed data on crashes and the number of miles driven by 16- and 17-year-olds, based on statistics from the National Highway Traffic Safety Administration fatality analysis reporting system and other sources.
There were 2,266 records of drivers in that age group killed in crashes over the study period of 2007 to 2010, AAA said.
Reporting By Alex Dobuzinskis in Los Angeles; editing by Cynthia Johnston and Mohammad Zargham