This de facto motto that Harley-Davidson had adopted is more than just a tag line. In all likelihood, there is probably as much truth and substance to it as there was to that temporary campaign they once used specifically to target women, which simply stated, "it vibrates." Like it or not, the obnoxious levels of noise emanating from a loud bike (could also be crotch-rocket) makes them hard to miss, and presumably (importantly) more difficult to accidentally not miss, but hit.
Sure, there is probably a sizable number of bike owners out there that simply feel cool or stroke their egos by how loud they can be, but the safety by-product of that has no doubt saved a considerable number of lives.
The noise cars make gets plenty of attention to. The aftermarket has had to deal with all sorts of noise ordinance when it comes to exhaust systems as tuners and hot-rodders go well out of their way to create a custom sound. Even the import market caters to this craving with brands like Tubi and Borla servicing Ferrari, Porsche and other brands.
As far as road-going vehicles go, however, there probably aren't two single vehicles on the road today that are more dissimilar than your average Harley Fat Boy and say, the Toyota Prius. Yet it's the Prius that is at the center of debate in Maryland not for the noise it makes, but rather the noise it doesn't, which apparently is just as much a problem.
And we thought the Toyota Prius emissions issue in Georgia was a problem.
The National Federation for the Blind has recently dug into the lack of noise associated with hybrid vehicles relative to the safety of pedestrians, sightless and otherwise, to see if there is a negative effect to not having any audible clues. This is perceived as a particular risk in urban environments where blind people rely on such clues to safely navigate roadways and their intersections. This is the same environment where hybrids are typically running at their quietest under electric power.
The argument is that a lack of sound from the vehicle puts the onus completely on the driver and less on the pedestrian to keep the two apart. These are the same drivers that are using cell phones, blackberries, food, coffee, hairdryers, books, newspapers, computers, navigation systems, and complex in-car entertainment systems to keep them occupied during the wasted time between traffic lights.
Personally, I don' think it will take a long, formal investigation into the matter to decide whether or not an issue exists. As more hybrids flood the roads, the number of instances where they creep up on people (never mind if they can see or not) is going to increase and the number of unfortunate collisions will as well. The trickier question is what type of standard noise will OEMs adopt that will create a safe atmosphere around their vehicles. You know the thought has crossed their minds and they probably have tested some sounds, but they should take a proactive stance on this or else an industry-adopted "noise" will be forced on them, and you can bet it won't be the whirling turbo effect or V8 rumble they had in mind, but likely a super annoying beeping reminiscent of a reversing cargo van.
You could probably make the argument that they only need the noise when operating under electric power as the combustion engines will produce at least something.
Who knows, maybe there is an opportunity hear. Maybe as long as the noise is of a certain level (volume), then you free to customize it how ever you want. There is huge money in allowing people to download ringtones for the phones, how far off can exhaust notes be?
So what would you have your hybrid sound like, a 1960's Ferrari? a landing 747? or how about a Harley? Or maybe you don't want something mechanical at all, like a roaring lion.
Come to think of it, that might set off a whole new set of issues, especially for those who can't see.