Originally Posted by
Daves_Not_Here
I think SlowNeasy is engaging in a regional practice. In the northeast United States, drivers regularly use their horns to communicate and the honks are taken in the spirit given - as a courtesy. These are light taps, half-honks. You can honk to communicate "hello, just giving you a heads up that I'm here", or "passing you now", or "thanks", and nobody (including cyclists) gets offended.
Do this in the west and people would misunderstand.
In this particular corner of the northeast US, honking usually just means "I'm pi--ed off at you", "you're going too slow", "you're in my way", "why didn't you run the red light so I could too?", etc. Once in a while it means "hey - I know you", followed by a wave. Around here, honking at someone you don't know is generally perceived as hostile, no matter what the intent is.