When I was in high school, our teacher taught us what the phrase "watch out" meant.
There is a joke about this. One day it was sunny day. One person was enjoying the beautiful view on his balcony. Suddenly he heard a voice, " watch out" from above. Then he protruded his head to see what happened. Then a person on top of the building was pouring a basin of water, which is just down his body, ... and he felt so bad because it smelled so stinking...
So, when you cross over the road, please by very careful. You need to watch out...