12 million plus pounds of litter were picked up off of North Carolina roadways in 2005. The N&O has a story on it here:
Last year, prison inmates and state highway workers removed 10.2 million pounds of litter from state roadways, at a taxpayer cost of $16.3 million -- up from 2004.
Private cleanup efforts netted almost 2 million pounds more in 2005.
I participated in the Neuse River Clean-Up a couple of weeks ago and lifted a whole canoe full of litter out of a three mile stretch on the Neuse and was followed by five other canoes filled to the top as well. On my way back from the event, I saw a woman throw a cigarette butt out of her window, and I almost went ballistic. I was so pissed that I spent all of my time cleaning up trash and had to watch someone litter in plain sight.