A New Report From AAA Foundation For Traffic Safety Finds That Young Millennials Are The Riskiest Drivers. Almost 90 Percent Of Young Millennials, Defined As Those Between The Ages Of 19-24, Engaged In At Least One Risky Behavior Behind The Wheel In The Past 30 Days. These Findings Come As Us Traffic Deaths Jumped Seven Percfent In 2015 To More Than 35-Thousand , The Largest Single-Year Increase In Five Decades.