There's an urgent warning for teenagers and their parents: the deadliest hazard to teens behind the wheel is other teens.

Dancing, singing and talking on cell phones. They can all lead to disastrous consequences on the highway.," said Dr. Flaura Winston of The Children's Hospital of Philadelphia. "Distractions are huge."

"The message that teens have gotten is that drinking and driving are a problem, but it's so much more than that

According to a new study, the biggest distraction by far is other teenagers.

The most dangerous scenario is teens and tweens riding without seat belts with new teenage drivers on high-speed roads.

In fact, more than half of kids who died in car crashes had teen drivers.

The study also found that a teen driving with one passenger doubles his or her risk of a fatal car crash.

Other dangerous circumstances for young passengers included drivers who have been drinking, male teen drivers and driving on weekends.