Motor vehicle crashes have long been one of the primary causes of death and injuries among teen drivers. But a new study by AAA finds that young motorists are also a danger to everyone else on the road. In all, nearly 3,000 people were killed in teen crashes in 2013, according to the AAA Foundation for Traffic Safety, with nearly 400,000 injured. But a new AAA study finds that nearly two-thirds of the people injured or killed during a crash are people other than the teen behind the wheel.