The Toyota Prius runs pretty quietly, especially when in electric-only mode. Hybrids in general are increasing in number. There are new electric vehicles like the Nissan Leaf about to hit the market and MINI is currently putting a toe in the water with its lease-only E. So, apart from a Harley-Davidson or two, the roads looks like it's becoming blissfully hushed.
Not if an alliance of automakers and advocacy groups such as the National Federation for the Blind has anything to do with it. For them, silence isn't golden but fraught with danger for the sight-impaired and distracted pedestrians. Apparently, cars under electric power need to be 40 percent closer to a pedestrian before they're detected (which does reduce safety margins and reaction times by an appreciable amount). Now this alliance is lobbying the government for legislation. Hybrids and EVs will be required to have an alert sound that the driver cannot disable. Congress is currently studying other auto safety proposals and this one is expected to be among them.
Carmakers are already on the case. Nissan will fit some kind of audible alert to its Leaf and General Motors plans on making its upcoming Volt plug-in hybrid emit a chirp at low speeds (at higher speeds, wind and tire noise could be sufficient). The Lotus Evora 414E is a hybrid concept that has a number of different engine and futuristic sounds to select from, courtesy of its HaloSonic Internal and External Electronic Sound Synthesis system, including the rumble and growl of a V12. It will even simulate a drop in revs when the driver changes up a gear, and rise when the throttle is re-applied.
However, if someone thinks they could customize the sound of their hybrid or EV and have the thrilling bark of a V8 without the fuel bills or emissions guilt, the proposed bill doesn't allow that.
Put "hit by hybrid car" into Google and it doesn't have a long list of tragic stories where blind people have been involved in accidents with silent cars. The most common story is one where an eight-year-old boy got hit because he rode his bike out of his driveway and onto the road. Thankfully, it wasn't a serious incident. He was neither blind nor deaf, just busy being an eight-year-old boy. It could be argued that if this proposed law saves just one life, it would be worth it.
The National Highway Traffic Safety Administration will draft legislation over the next 18 months. After going through the red tape, it could become law in three years.