On July 20, 2006, about 1055 mountain standard time, a Cessna 175, N6516E, veered of the runway and collided with a vehicle while landing at Show Low Regional Airport, Show Low, Arizona. The pilot/co-owner was operating the airplane under the provisions of 14 CFR Part 91. The private pilot, the sole occupant, sustained serious injuries; the airplane sustained substantial damage. The personal local area flight departed from Show Low at about 1020. Visual meteorological conditions prevailed, and a flight plan had not been filed. A National Transportation Safety Board investigator conducted a telephone interview with a witness about 10 minutes after the accident transpired. He stated that while taxiing his airplane, he observed the accident airplane on the final approach leg of the traffic pattern for runway 21. The accident airplane touched down on the runway surface just upwind of the runway identifier markings (numbers). The right wing lifted and the airplane subsequently veered to the left of the runway centerline. The airplane continued left off the runway and encountered a ditch that was situated between the runway and taxiway. The witness further stated that after encountering the ditch, the accident airplane bounced and became temporarily airborne. The airplane continued toward the taxiway. He heard the engine increase in revolutions per minute (rpm), which he thought was consistent with the pilot attempting to make a go-around. The airplane headed toward a row of hangars and collided with a vehicle. The witness taxied to the accident location and aided the pilot with shutting down and securing the engine. The pilot told him that she had problems landing and then did not have enough time or engine power to become airborne again. The witness added that he had been watching the accident airplane prior to the mishap. He observed the pilot perform about four to five touch-and-go practice takeoffs and landings. He estimated that the wind condition at the time of the accident was about 8 to 10 knots from a southerly direction. In a written statement, the pilot reported that she completed four practice touch-and-go takeoffs and landings on runway 21. On her fifth landing, the airplane touched down and subsequently swung to the left. She experienced a loss of directional control and opted to perform a go-around by increasing the engine power. The airplane continued to the left of the runway and collided with a vehicle. The pilot reported no preimpact mechanical malfunctions or failures that would have precluded normal operation. The Airport/Facility Directory, Southwest U. S., indicated Show Low runway 21 was 3,937 feet long and 60 feet wide.