We know, of course, that people aren't going to take the steps you mention.  They will roll down a window, hand out some change, a buck or two, maybe some pop or a can of food, etc..then, drive on when the light turns green.  

You, in your last sentence, dismiss helping others as merely a selfish exercise to make yourself "feel good." That's a rather sad, cynical view of mankind.  If a person's values include altruism, including donations to organizations and individuals, is there something paticularly wrong with feeling good about acting on those values?  If I value honesty, a clerk gives me change for a twenty when I presented a ten, and I tell him/her so and return that "extra" ten, am I just selfishly do so to make myself "feel better"?  If as married person you're faithful to your spouse, are you being so just to make yourself "feel better"   We all have values and honoring those values should make us "feel good."  For many the charity of helping others represents such a value.