On January 7, 2005, about 1730 mountain standard time, a Piper PA-28-151, N151MM, struck a taxiway location sign during landing rollout at Ryan Field Airport, Tucson, Arizona. International Aviation Training Academy was operating the airplane under the provisions of 14 CFR Part 91. The student pilot, the sole occupant, was not injured; the airplane sustained substantial damage. Visual meteorological conditions prevailed, and a flight plan had not been filed. The local instructional flight originated about 1700. In a written report, the operator stated that the student performed three solo takeoffs and landings. On the student's fourth and final solo practice landing, the airplane touched down on runway 24L. The pilot maneuvered the airplane off the runway centerline and prepared to exit the runway at taxiway B2. Approaching the taxiway, the pilot applied strong brake pressure, attempting to dissipate forward speed, and began a turn onto the taxiway. The turn shifted the airplane's weight distribution, and the pilot, worried that the airplane would tip over, compensated by stopping the turn. The airplane overran the taxiway and struck the taxiway location sign, incurring damage to the right wing and aileron. The operator added that it was the student's first solo flight. The pilot reported no preimpact mechanical malfunctions or failures with the airplane.