LOS ANGELES (CBS) — The risk of death from automobile accidents among teenage drivers increases when other teens are in the car, a new study found.

Researchers for the AAA Foundation found the increase is caused by added distractions, such as cell phones. The study also revealed that the risk of deadly accidents increases for every added young person in the vehicle, while it decreases when there is an adult to supervise.

Transportation Secretary Ray La Hood said there are many things teen drivers can do to keep away from the already dangerous distractions.

“When you get in a car, buckling up,” Hood said. “No drinking and driving. Both hands on the wheel. No texting and driving. No cell phone use and driving. All of those things go a long long way to saving lives.”

The AAA Foundation study on youth driving also found that summer months are more dangerous than any other months of the year. KNX 1070 reported that 420 young drivers die in accidents during the summer, compared to about 360 during the other months.