Ok, since the thread has drifted slightly toward safety and the use of the horn I'll weigh in with my life experience. To date, I've been legally driving for over 55 years, never a chargeable accident or ticket. And yes, I've driven many many miles per year as my job required it. I have used the horn one time that I can remember. Going back about ten years found me northbound on I-75 in south Florida, running with heavy traffic. I was driving a diesel pusher motorhome, air brakes, pulling a Ford explorer that was set up with correct towed brakes. I was grossed at somewhere near 30K lbs. Traffic was all running about 70 MPH, me in the right lane. Ahead I saw this car coming up the acceleration lane, obviously going to merge into traffic so I said myself, "He'l hit it as he gets closer". Being the cautious driver I am, I backed down as I could not merge left. The driver never did accelerate. The point of no return was closing for me, I had no where to go, did I mention traffic was heavy. So the one time that I can remember using the horn was then. I had killed off enough speed to let the car in but I layed on the air horn, one solid extended blast. I'll never know if the driver was asleep, inattentive, or just a poor driver, but he did not pull into traffic. Perhaps I was just being an *** in the use of my horn that day but it got the driver's attention. Did the driver learn some awareness, I hope so. Was use of the horn necessary, probably not. Did I feel better at the time, yes Would I do the same thing again, probably yes, as I see it as a learning experience for the other driver.
Forgot to mention that I always drove with lights on when I drove that rig.

 

I rode the steam train thru the mountains in northern NM last Fall, and as you can imagine part of the experience was hearing the locomotive's whistle firsthand. The conductor told us that the whistle could be heard plainly for 3 miles, even in the mountains, and much further on the plains. I believe it, lots of energy there!