Honk.

I was on my way to a class today, when I heard a car honking it's horn...I looked to see what the problem was -here in Santiago you usually hear honking only if there is a problem or you are mad and in a hurry-and what to my wondering eyes did appear...but a regular car honking at the police car in front of him because the traffic light had turned green. Is this normal?! What a different reaction from what we would see in the US.