Highway Litter -- Don't do it!

Littering is one of my many trash-related pet peeves. Why do people litter? Is the world their trash can?
A recent article in local paper listed some of the debris items found by Department of Transportation workers doing road cleanups: syringes, satellite dishes, appliances, tires, cigaratte butts, human waste in plastic bottles also known as "trucker bombs", lumber, furniture, kitty litter, supplies to make meth-amphetamine, box springs, motor-oil containers, paint thinner,food cartons,plastic bags and soft drink bottles...
Trash on the freeways increased 182% over last year.
Why? Can't people just find a proper trash can? They could recycle it; put it on Freecyle.com where people put stuff they no longer want or need. How hard it is to take it home, or wait until you get to wherever you are going to toss it? For no other reason, think of the safety issues if the tossed item blocks someone's vision or causes them to swerve.
Please don't litter. It is that simple.