On November 10, 2010, about 1657 mountain standard time, a Piper PA30, N628R, collided with a light post and a building during taxi after landing at Tucson International Airport, Tucson, Arizona. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The airline transport pilot with a certified flight instructor (CFI) certificate was not injured. The airplane sustained substantial damage to the right wing. The cross-country personal flight departed Stellar Airpark, Phoenix, Arizona, at 1520, with a planned destination of Tucson. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot reported that his thinking had been impaired all day. He had a severe headache, and he was having trouble with his left side motor skills. The pilot flew from Tucson to Phoenix earlier in the day to complete a flight check for his CFI renewal. Due to the headache he was experiencing, he terminated the check ride during the oral examination. The pilot returned to Tucson, and landed on runway 11L. He could not slow the airplane down by taxiway A11, so he continued to taxiway A13. He was unable to stop the airplane prior to crossing taxiway A or execute a left turn. The airplane continued forward until it struck the Fire Department warning light post with the right wing tip tank. Fuel began escaping as the airplane continued forward into the Fire Department's plate glass window. The pilot estimated that his speed at the point of contact was 5 miles per hour, and he stated that he did not hit his head. The pilot reported no mechanical failures or malfunctions with the airplane. Several hours after the accident, the pilot's wife noticed that he was shuffling his left foot. He stated that he was still feeling the severe headache that he had at the start of the day. He went to a hospital that night for examination. Medical personnel discovered a subdural hematoma and they performed immediate surgery to remove blood from his brain.