I think I can count on two hands the amount of times I've used my horn in 20 years of driving. It's used for when I think someone hasn't seen me (ie. reversing

I think I can count on two hands the amount of times I've used my horn in 20 years of driving. It's used for when I think someone hasn't seen me (ie. reversing), or if the lights have turned green and the person isn't paying attention. The latter will be a bump on the horn (so about 100ms) where I doubt it gets up to full volume. People are quite happy to wind down the window in order to show their displeasure with a hand gesture where I live.