Along with that, I was under the impression that dump trucks had to have a cover on the rear when they were loaded with rocks, gravel, dirt, etc., so it wouldn't shoot out at the cars behind them... I have seen so many that are not covered, that I think I am making it up in my mind that there was a law passed stating so. It is so annoying watching crap fly off the back of those trucks onto traffic. I stay far far far back when I see them, which is often. That really bugs me...