A new study shows that teen driving gets riskier the more teens are in the car -- data unfortunately reflected in recent car accidents in the Washington area, according to AAA Mid-Atlantic.

The new study by the AAA Foundation for Traffic Safety -- released in time for Teen Driver Safety week, which takes place this week -- shows that 9,578 16- and 17-year old drivers were involved in fatal crashes between 2005 to 2010, and nearly 4,000 of those had at least one teen passenger.

That story played out in three different crashes in Northern Virginia and Maryland from July to September. Altogether two 17-year-old drivers, a 17-year-old passenger and a 16-year-old passenger were killed in the crashes, according to an analysis by AAA Mid-Atlantic.

"This much is certain: mixing teen drivers with teen passengers is simply toxic," said AAA Mid-Atlantic's John Townsend in a statement. "It is imperative that in order to avoid these types of tragedies that parents and guardians set and consistently enforce family rules that limit newly licensed teens from driving with other passengers unless they are adults serving in a supervisory capacity. Newly licensed teen drivers need to be concentrating solely on the rules of the road, not distracted by their fellow teen passengers."

Teen drivers were speeding in 30 percent of fatal crashes, but that number went up to 48 percent when three or more teen passengers were also in the car, AAA said.

Late-night driving and alcohol use rates also went up with more teen passengers.

The data adds to a May report from AAA that showed that 16- and 17-year old drivers involved in crashes were 44 percent more likely to die if they were with one passenger younger than 21, and twice as likely to die if they had two passengers under that age.

Teen drivers are in more crashes per mile than any other age group, AAA reported.