In the city, I see more and more drivers not using turn signals when they turn. In the country, I see drivers passing at 40 and 50 mph not using turn signals.
It's even worse on the Thruway. Cars zig-zag at 60 (or more) from the right to the left lane and even from the left inside lane across two or three lanes and off the ramp at the extreme right, not using turn signals. Aggressive driving, they call it now.
If courtesy is not in a driver's agenda, safety should be.