I try to be nice and the people I'm around day-to-day are nice (like my coworkers, people at the grocery store, etc.) Also I can't recall people being nasty at Disney either. Well, I take that back, there was one time I witnessed a dad with stroller repeatedly bump the person in front of him and they got into it, but other than that...
but you're right about on the road. Something about driving seems to bring out the worst in people, but to me, so much of that is more stupidity than outright meanness. I feel like a lot of people need refresher courses on driving.