> Let me tell you, when someone is blissfully wandering into your lane, or otherwise driving recklessly, having a horn is an essential safety device to let other motorists know of your presence.

What happens when you use it? Do they suddenly start paying attention and stop driving recklessly? I ask, because I've never used my horn whilst driving; I've only ever used it for alerting someone reversing into me whilst I was stationary.

If I see someone drifting into my lane, then I back off by applying the brakes. If someone is swerving, then I also slow down. Generally I slow down or change lanes but I've never used the horn.