Daily usage of communication

I drive to college everyday. A few things which we are bound to see everyday makes me wonder. The traffic lights – are they a sign of non-verbal communication? The traffic police directing the traffic during morning peak hours, just with the movements of his white-gloved hands, he is able to direct the cars, another sign of non-verbal communication? Cars, turning on their signal lights to indicate a left turn or right turn, another sign of non-verbal communication? All those mentioned above, are very good examples of non-verbal communication which are easily interpreted and obeyed.
HOWEVER, how many are in full awareness of the importance of these non-verbal communications I have mentioned? Miscommunication in these few aspects results to DIRE consequences = ACCIDENTS, which at certain points, causes the loss of lives. Turning off suddenly without signaling the signal lights or charging through the so easily visible RED light which indicates stop causes road accidents to occur. Such miscommunication happen everyday, everywhere.
This is just an example of the usage of communication and the results of miscommunication.