On November 19, 2004, at 1125 eastern standard time, a Cessna 172S, N2120M, was substantially damaged during a collision with a parked construction vehicle at Mansfield Municipal Airport (1B9), Mansfield, Massachusetts. The certificated student pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local instructional flight, conducted under 14 CFR Part 91. According to the pilot's flight instructor, the pilot had flown the airplane solo twice previously. The pilot then did not fly for approximately 30 days. The pilot discussed returning to flight training and the flight instructor stated that he wanted the pilot to fly with an instructor before he could fly solo again. The pilot returned to the airport on the day of the accident and was dispatched an airplane without the instructor's knowledge. According to a written statement submitted by the pilot, he encountered barriers blocking the taxiway, and due to the angle of the barriers, as well as the fact that he saw another airplane holding short of runway, he thought that it was appropriate to proceed past the barriers. According to a witness, he was standing about 100 yards beyond the barriers, and in the middle of the taxiway, when he observed the accident airplane going around the barriers to the left side and into the construction area. The witness began walking toward the airplane and waving his arms in the air in an attempt to alert the pilot. The pilot stopped momentarily behind trucks parked on the right side of the taxiway, then continued down the taxiway about 4 to 5 feet left of the centerline. The left wing of the airplane struck a construction vehicle parked on the left side of the taxiway. The airplane pivoted left and impacted the right side of the vehicle. When the witness asked the pilot why he did not stop, the pilot stated that he thought he had seen other airplanes go through that area. The weather reported at Taunton Municipal Airport (TAN), about 11 nautical miles southeast, at 1152, included winds from 330 degrees at 9 knots, 10 statute miles visibility, and clear skies below 12,000 feet.