On June 28, 2001, about 1330 hours mountain standard time, a Mooney M20C, N311X, owned and operated by the pilot, taxied into a motor vehicle traffic sign at the Tucson International Airport, Tucson, Arizona. The airplane was substantially damaged, and the commercial pilot was not injured. The personal flight was performed under 14 CFR Part 91. Visual meteorological conditions prevailed at the time, and no flight plan was filed. The flight originated from the La Cholla Airpark, in Tucson, about 1300. Information received from the Tucson airport police indicated that after the pilot landed he had intended to taxi to a fixed base operator via taxiway Delta. However, he became confused and turned onto a perimeter road, believing that it was the taxiway. As the pilot was proceeding on the road, he collided with the back side of a "yield" traffic sign. The pilot reported that just prior to the collision he had directed his attention toward military jet airplane traffic that was in front of him and proceeding away. He also indicated that the sign was small and inconspicuous.