Abstract: Two employees were testing a Department of Defense Humvee on a rough-terrain track behind the manufacturing facility. One employee was in the vehicle and a coworker was operating the vehicle remotely with a hand-held remote control unit. The employee was in the driver seat acting as a safety rider. He was equipped with an emergency stop switch that only activated the brakes, as well as a hand-held radio. The employee was utilizing the seat belt, but did not have head, face or eye protection nor was he wearing any flame retardant clothing in the event of a fire. The vehicle was equipped with a roll bar that was attached to a plate for rooftop equipment. While testing vehicle on the rough terrain, the vehicle was operating at a speed that the employee did not feel was safe for the vehicle to negotiate an upcoming turn. The employee activated the emergency stop which locked the brakes. When the brakes locked, the vehicle rolled on its side and ended on its roof. The employee unbuckled himself and exited the vehicle. He was transported to a local hospital for evaluation, but was not hospitalized for the bruises he sustained.