but can accurately detect where they are.
From what range, 2 inches? Maybe if you lined up A-J across the road edge-to-edge it would have a hard time getting around them, but I'd like to believe that the sensors would be able to observe an obstruction from far enough ahead that it would be able to stop safely in this event. So instead you have A-J moving about. The laws of physics mean that nothing can simply teleport in front of us, nor can anything attain infinite acceleration, so we can detect the vehicle, child and/or dog that is moving towards our current path well before it cuts us off.
D) would probably be the worst hazard of the lot, since being light-weight it would be able to accelerate and change direction much faster than most of the other obstacles. Worst case, having come to a complete stop to wait for it to cross the road, the vehicle is blocking the breeze that was pushing it in the first place, leaving us at a standstill.