DIX HILLS, N.Y. (CBSNewYork) -- The stretch between Memorial Day and Labor Day is known as the 100 deadliest days for teens, when they are out of school and on the roads.
As CBS 2's Kathryn Brown reported Thursday, the most dangerous thing teens are doing may surprise you. And it may be sitting right next to the teens as they drive.
"I drive my siblings every morning to school, and they are actually very distracting when it comes to driving," said Alex Rosenzweig, 18.
It's not texting, or even talking on the cellphone that's the biggest distraction, according to the National Safety Council.
The council said the biggest distraction is actually passengers – who they are, and how many.
A new study found teens were 44 percent more likely to be involved in a fatal crash when they had passengers in the car with them.
"If something's going on in the back, or someone says something that really gets you thinking, you're just not focused," said Matthew Kipman, 18.
"Every once in a while, I have to tell everybody to, you know, simmer down," said Glenn White, 18.
Driving instructor Earl Schleicher agreed that passengers can be a major distraction.
"They're just not keeping 100 percent on the driving task; that's what's really needed," said Schleicher, of Bell Auto School.
Most states now have a graduated license program. In New York, new drivers have to get a junior permit - and are restricted to two passengers -- and driving only to work.
In New Jersey, a probationary license allows 17 year olds just one passenger, along with a parent.
Last month, five teens were killed in a car crash in Farmingdale, Long Island, and last year, four teenagers were killed on the Southern State Parkway.
In both cases, a 17-year-old was behind the wheel.
In fact, nearly 1,000 people were killed nationwide in accidents involving teen drivers in 2012. More than half of them were teenagers.
As summer approaches, a wrecked car sits on the front lawn of Half Hollow Hills High School in Dix Hills. It serves as a visual reminder to teens of the dangers they face on the roads.
"Just seeing accidents and stuff, like, my parents are more strict with me because of it," said Monica Benitez, 18.
Driving instructors say restricting who is in the car can be the difference between life and death.
Experts also said mapping out unfamiliar routes ahead of time can also reduce anxiety and uncertainty behind the wheel.
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