What's up with people just throwing trash out of their cars?

This of course isn't unique to New Haven, but I do see it a lot around. People just throwing trash out the window. Usually fast food bags/cups/wrappers. It's gross.

I even see people in the drive thru at McDonald's throw their last McDonald's bag out the window. There's literally a trash can in the drive thru, and like 5 trash cans in the parking lot.

Do these people just not have trash barrels at home? Can they not throw their trash away at the gas station when they're filling up their tank? What's actually wrong with these people? How is a grown adult OK with littering for absolutely no reason?