Transportation cyclist here. This is a great article, but it only indirectly touches upon one of the most effective tools a cyclist could have: an air horn. I have an Air Zound air horn and I feel much less safe riding without it. I'll often give a few toots before approaching an intersection to increase the chance that I am seen. And it has probably saved me from some major crashes when I lay down the horn on someon…
I am a US transportation cyclist. I mostly dislike vehicle (including bicycle) horns. If it's a close enough call with another vehicle, my voice has been enough of a 'horn' to alert drives. If there's a less close conflict, then there's probably positioning/visibility change that should have happened upstream. For me, horns are a too frequent, rude disruption in the world.
I agree that horns can be rude and disruptive, and perhaps most honks are. But I stand by every time I've used mine. I don't use it frivolously. Whereas drivers seem to use their horns frequently because they are impatient, I use it only because I'm in danger.