A volunteer performs the "Walk-and-Turn" sobriety test during a driving under the influence training course at Hulrburt Field, Fla., Sept. 5, 2013. During the test, subjects were directed to take nine steps, heel-to-toe, along a straight line. Then, they were told to turn on one foot and return in the same manner in the opposite direction. (U.S. Air Force photo by Senior Airman Krystal M. Garrett)