Why would I suggest this, you ask? Well, I am currently sitting on a tour bus taking me and 16 other people from Mai Chau back to Hanoi. The ride is 4 hours, and my plan had been to sleep. Within minutes of getting on our overpacked (there's a girl sitting on a stool because there were no seats left) minibus, the horn honking started. In fact, our driver keeps one hand on the horn at all times...just in case.
I've experienced this throughout Vietnam. While it appears that there are no traffic laws, there are some unspoken rules of the road, and specifically rules regarding honking. What I've gathered thus far is the following:
(1) Honk your horn if you are passing someone from behind to give them warning.
(2) Honk your horn if someone is turning onto the road you are on, just in case they didn't see you.
(3) Honk your horn if you want someone to move out of the way.
(4) Honk your horn if you are passing a vehicle on a blind turn to give oncoming traffic notice that you may hit them.
(5) Honk your horn in response to someone else honking their horn.
(6) Honk your horn at any pedestrian crossing the street, even if there is no chance of them being in your way.
(7) Honk your horn to give notice that you have arrived to pick someone up.
(8) Honk your horn if you are going the wrong way down a supposedly one-way street.
(9) And just in case there is no one else anywhere on the road near you, you can honk your horn then, too. I guess it's some sort of celebratory honk.
(10) I'm sure there are many other horn honking rules that I have yet to pick up on.
Due to my inability to sleep with the incessant honking, I decided to conduct a little experiment.
Methodology: Set phone timer to 5 minutes. Count how many times in the 5 minutes our driver honks the horn. Repeat 5 times.
I should note that these were all conducted in various conditions ranging from a town where school was getting out to an open stretch of road with no one else on it.
20 honks/5 minutes
14 honks/5 minutes
20 honks/5 minutes
35 honks/5 minutes
Average of 22.4 honks/5 minutes or just under 4.5 honks per minute.
Given the above information, and the fact that this ride is 4 hours long, I've extrapolated the data to determine that our driver will have, on average, honked his horn over 1,000 times during our drive. This does not account for the length of honk, which ranged from under half a second to 3-4 seconds.
Given this information, coupled with the fact that I have heard this incessant honking on almost every vehicle I've been in, I think a temporary ban of horn honking in Vietnam would be entertaining to watch how the driving changes, and quite pleasant for everyone's eardrums.