I leave plenty of room in front to avoid all those things.
Should be a law about those truck beds being so short that a headache rack be required. It's just plain not right to be traveling with lumber sticking out the back of a pick up bed. A guy was killed by a lady running some lumber back home when it all swing out on a turn. She was picking it up when a biker tried to avoid it and died. It was one of those super shorty beds that need a forward rack.
Also the Dodge Ram spar tire cable (holds spare underneath) rusts so watch out for those too.