Visual pollution caused by littering is pollution, just as is water pollution and air pollution. The problem is that we Americans want immediate gratification in every aspect of our lives. For some people, littering at 60 mph is instant gratification. You toss that cup out of your window while traveling so quickly that you don't even see the cup land. If you don't see it land, you do not have to feel badly because, in your mind, the litter evaporates rather than pollutes.
Debris comes in all shapes and sizes, and can be lethal as well as unsightly.
According to federal government statistics, in 1997 over 150 people died in debris-related vehicular accidents. While we generally don't think about road debris as potentially lethal, it is very dangerous. Perhaps the most famous debris-related death occurred last November when film maker Alan Pakula was killed after his vehicle was struck by a steel pipe left on a Long Island highway. According to published reports, the pipe was hit by another vehicle which propelled it through Pakula's windshield. One month before that accident, another person died when his car swerved to avoid a shredded tire.