[is0tope]

Horns definitely have a use, a fact that was made clear to me when driving a bike in Vietnam (horn is critical to let people know you are passing in a big group).

However, what should be penalised heavily is blaring your horn in frustration or when stuck in traffic. This happens near where I live on a daily basis, and causes my blood to boil. It seems for these people it is almost instinctual, and they will do it at the slightest slowdown or inconvenience.

Not a big fan of enforcement actions, but this is incredibly anti social and provides zero/negative utility. A couple of weeks of police camping intersections and handing out liberal fines might perhaps encourage a change in behaviour.