NASHVILLE, Tenn. (WKRN) – The 100 “deadliest days” for younger drivers are underway, according to AAA.

It’s the time period between Memorial Day and Labor Day that teen drivers are most vulnerable on the roads, with 30% of deaths involving teen drivers nationwide occurring within those 100 days.

“Summer is historically a dangerous time for teen drivers,” Megan Cooper, a spokesperson for AAA, said in a statement issued this past week.

New teen drivers are three times more likely to be involved in a deadly crash compared to adults, AAA reported. Crashes are also the leading cause of death for teens 16 to 19.

“Now that school is out, teens will spend more time on the road, often driving with friends at odd hours of the day and night. Because of their inexperience, teens are more susceptible to dangerous driving behaviors — like speeding, driving distracted, and not wearing a safety belt,” said Cooper.

Inexperience, obviously, is a major risk factor. But so is distracted driving, which accounts for nearly 60% of crashes involving teenage drivers. Those distractions include phones and “infotainment” systems, AAA says, but the biggest distractions are the drivers’ teenage friends in the passenger seats.

In a 2012 report, the National Highway Traffic Safety Administration (NHTSA) analyzed data from multiple studies which determined that risky driving behaviors increased with the number of teens in the car. Just one teenage passenger increases risk by 2.48 times, the NHTSA noted, and two or more teen passengers increase risk by 3.05 times.

“In fact, research shows that the risk of a fatal crash goes up in direct relation to the number of teenagers in the car,” the NHTSA wrote.

The NHTSA acknowledged, however, that teenage passengers were 10 times more likely to make encouraging or helpful comments to the driver (pointing out hazards, helping with directions) than they were to be observed making comments “encouraging risk-taking behavior.”

“There were many more instances of passengers assisting the driver — or admonishing the driver for ‘bad’ behavior — than actively encouraging the driver to do something risky,” the NHTSA wrote in its 2012 report.

The increased risk, the NHTSA said, was more related to “loud conversations or horseplay” happening in a car with multiple teens.

AAA is urging parents to “model safe driving behavior” and be involved in their teen’s learning process.

“Spend time coaching your teen while they’re behind the wheel and have a serious discussion about safety. While parents can be a great teacher, it also helps to seek out professional training courses, like those provided by AAA,” said Rachel Wilson, the director of driver education programs for AAA.

AAA also suggests its 25-hour online driving course to help reduce a teen’s risk behind the wheel, or its database of training-course recommendations.