Continual walking (to, inside, and around bus), sitting, standing, squatting, stretching, bending, kneeling, stooping, twisting, turning, climbing bus steps, pushing, pulling, carrying, reaching, repetitive hand and arm motions (steering, driving, shifting), lifting (50 lbs. or more), talking (announcing streets, talking on radio), seeing (traffic lights, inspections, passengers, stopped vehicles, traffic conditions), hearing (traffic sounds, emergency vehicles, passengers, radio, mechanical problems).