Can we stop the loud-beep on backing up?
One of the scourages of urban areas is the requirement (I presume) that heavy equipment make a loud beeping noise when it's backing up. It's meant to warn anybody standing behind the vehicle, presumably because the driver doesn't have the same field of vision to see you, and because people are more wary of standing in front of a moving vehicle than behind it.
As such, as we all know, the sound is really piercing. And more to the point, it travels, often for miles. It's a major noise pollution anywhere near any work site. I presume part of the problem as well is workers wearing hearing protection need it even louder.
So my challege is, can we do a better job? Can we make an attention getting sound that is more directional (aimed backwards, and perhaps down from the top of the vehicle) so it won't travel as far or distract people not behind the machine?
Can we standardize rear-view cameras, which are so cheap now, so that the operator's view of what's behind is top notch?
Can we combine a quieter sound with really bright, moving lights, the kind you would see on the ground if your back were to the beeping machine? Could we blow air with high pressure streams or those long-distance vortexes like the AirZooka makes, or would this be too much of a problem with dust (or in wind?)
Can we have object detectors that spot objects in to the rear of the machine and make the beeps louder when there is something? (Admittedly they are going to go off for a wall or wheelbarrow as much as a guy, and they have to be really reliable because people would start depending on them to know how much caution to use.) Perhaps they can detect that everything they have seen has left the area and reduce the beeping, because if there is one person behind the truck, that assures you somebody is watching and will move anybody who doesn't see the lights or hear the beeping.
I solicit other ideas to safely warn people about moving equipment that don't ruin the peace.
Update: I received information from a firm called Brigade which [claims to have an answer](http://www.brigade-inc.com" rel="nofollow). They use white-noise alarms. They claim they are easier for us to echolocate than less natural pure-tone sounds, and I agree that they disperse into the environment more quickly so they won't travel. The piercing alarm has been chosen in the past as it is un-natural and thus stands out more from background, but that means it travels further. Natural sounds fade from notice more quickly but possibly are just as recognizable close up.