I can not prove it, but would "bet the house" that individuals function better and treat others better in a clean environment.  A clean environment sets expectations of higher behavior.  A clean environment not only enhances our quality of life and the natural beauty of this country but the value of property.

Picking up a piece of someone else's trash isn't easy.  But doing so is an act of leadership and gives others incentive and permission to do the same.  It shows others that you are willing to help keep their world/environment clean.  Like many citizen actions, this one is a small but important sacrifice and gift to others.

Picking up a piece of trash each day is satisfying and gives one a feeling of doing something beyond themselves.  It's also a daily reminder of the need for each of us to do things to keep the country strong.

If you go for a walk or take a picnic, take a plastic shopping bag.  You can actually use the plastic bag to pick up the trash if you don't want to touch the trash.  Keeping some plastic bags in the glove compartment of our vehicle(s) also helps ensure that we dispose of our trash properly.

In some states, the "Highway Department" allows organizations to be responsible for keeping portions of a highway clean and for doing that the organization's name gets posted on a sign on the highway.  Adopt-A-Highway Liter Control program.