On October 13, 2002, about 1525 Pacific daylight time, a Piper PA-28-151, N75164, collided with a runway sign while taxiing following a landing on runway 29 at the San Luis Obispo Airport, San Luis Obispo, California. The student pilot had rented the airplane from Cal Coast Flyers, Inc., San Luis Obispo. The airplane was substantially damaged, and the pilot was not injured. The solo instructional flight was performed under the provisions of 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated from the airport about 1430. According to Federal Aviation Administration air traffic controllers, who witnessed the accident, after the pilot made an intended full stop landing she was instructed to exit runway 29 at intersecting runway 25. The accident pilot acknowledged the instruction and began a left turn onto runway 25. Then the airplane was observed to turn right back toward runway 29. On this new course, the airplane entered a grass-covered median area between runway 25 and taxiway "J," and thereafter, collided with a 2,000-foot remaining distance marker, which was located near the left side of runway 29. (See the airport diagram for a sketch depicting the airplane's track, and the location of the impacted sign.) Following the collision, the pilot turned left onto taxiway "J" and proceeded to the parking area. According to the pilot, the accident occurred while she was practicing takeoffs and landings in the traffic pattern to gain proficiency toward obtaining a private pilot certificate. The pilot indicated that she collided with the sign after making her sixth landing, while attempting to exit the runway following receipt of the air traffic controller's instruction. An official from the Airports Division, County of San Luis Obispo, filed a report with the airport manager regarding the mishap. The report indicates that during the collision sequence the airplane's left wing was damaged. The wing's leading edge was crushed and ripped open in two separate locations; one just left of the fuel tank and the other 2 feet outboard of this location. In each case, leading edge skin was bent rearward to the vicinity of the wing spar. Each of the crushed areas exceeded a span of 12 inches. The National Transportation Safety Board investigator has not received the required "Aircraft Accident Report" from the student, or any written statement from her.