Those who signal lane changes, and those who don't. As a teen I took Driver's Ed. I was taught you always signal a lane change. It's the law, and it's the right thing to do. So, I always signal lane changes. It's a habit.
Signaling a lane change sends a signal to the rest of the world that you are a) self-aware, and b) deliberate in your driving.
It is not only the safer thing to do, it is the courteous thing to do. It lets people know that you are aware there are other drivers on the road.
Conversely, failing to signal sends a signal that either you a) were never properly taught, b)are forgetful/sloppy in your driving habits, or c) really don't care about others or what they think.
I watched Litter-Guy drive off as the light changed. I watched him make two abrupt lane changes, sans signals. Somehow not signaling seems to fit being a litterer. Both are (at least mildly) anti-social behaviors.
Am I being too harsh here?
And that's not all. As I drove up beside the guy to get a look at him, I came to my next observation. Which I will tell you about.
And that's the way the blink-blink lane-changing Ball bounces.