The car horn has been around since the inception of the car, and it’s time for an improvement. In most cases, the honk is just an angry, wordless scream, and I don’t see how that’s helping. Occasionally it might communicate, “Hey you’re an idiot!” But is calling someone an idiot, ever going to make them less of an idiot? If anything, they will just get angry, and now you’ve created an angry idiot. Is that what you wanted?

Ultimately, the honk is bad because it’s rude and cowardly. People don’t behave that poorly in a face-to-face encounter. Say you’re walking down a busy sidewalk, and someone behind you accidentally trips you into oncoming foot traffic. The person you fall in front of will probably stop and help you up. They might even brush you off, and ask if you’re okay (they might even ask for your number, depending on your appearance that day). They certainly won’t just step over, or weave around, shouting as they go, “Get off the sidewalk asshole!”
“So sorry, I got tripped.”
“Whatever idiot, learn to walk!!”

But this is exactly what happens if you the equivalent happens in your car. Maybe you get hung out to dry in an intersection. You have no where to go, but people are wailing their horn at you. “Oh, thanks, I didn’t realize the intersection was the wrong place to be parked.”

My point is, there is much better communication technology available. Why not use a polite, automated GPS-type voice? I propose three different buttons. The first says, “Excuse me,” the second, “I’m sorry,” and a third, “I think you’ve made a mistake.”

Even for the person with anger issues, the worst they can do is hit a button that says (in a polite woman’s voice), “I think you’ve made a mistake.” The second car can tap, “I’m sorry,” and the road rage incident is stifled.

I suppose you could get into an epic battle of politely saying, “I think you made a mistake.”
“I think you made a mistake.”
“I think you made a mistake.”
“I think you made a mistake.”
Even then, I don’t think any guns will be pulled. They might even stop to think, “Hey, I did make a mistake,” at which point they can tap “I’m sorry,” and continue on to Dairy Queen, without any boiled blood.