Blind Pedestrian Crossing Road SignThe National Highway Traffic Safety Administration (NHTSA) has proposed a rule that would require electric cars to make noises to let pedestrians know they are near, as Angela Greiling Keane writes in a Bloomberg News article appearing in the San Francisco Chronicle.

The proposed rule, which was announced at the beginning of this week, would require sounds to be audible when vehicles are traveling slower than 18 miles per hour, so that electric and hybrid vehicles can be heard by bicyclists and pedestrians, especially people walking who are visually impaired, Keane writes.

NHTSA emailed Keane a statement saying the rule would save 35 lives in each model year of hybrid vehicles, and would prevent 2,800 injuries. Keane reports that the cost of adding external speakers to electric and hybrid vehicles (whose engines are silent when in electric mode) would cost about $35 per light vehicle, or about $25 million per year, according to NHTSA.

As this blog noted on July 12, 2011, the NHTSA was mandated to create the regulations by the Pedestrian Safety Enhancement Act of 2010. All vehicles of the same make and model must have the same alert sound.

Keane quotes Jesse Toprak, an analyst for industry data provider in Santa Monica, California:

To add about a $30 or $35 item to a car for this kind of injury and death prevention, it’s hard to argue against. I’m sure all of us have experienced at some time the fear of getting struck by a Prius.

In addition to needing to produce a sound when driving at speeds of up to 18 miles per hour, cars would need to produce sounds when going in reverse, Tom Gara writes for The Wall Street Journal blog Corporate Intelligence. Gara discusses what the cars could sound like under the new rule, once it is finalized.

He says one proposal was for the sound to be a recording of what a regular gas-powered car sounds like, “but that idea was quickly dismissed because it ‘would not ensure sufficient detectability.’” NHTSA has published a list or proposed sounds here:

Gara goes into the details:

The proposed noises are a set of quasi-futuristic whirring hums that sound a bit like what you would imagine an electric engine would sound like, if it didn’t actually sound like nothing at all. They are designed to change in pitch as the speed of the car increases. More precisely, according to the NHTSA, there should be a ‘one percent shift in pitch frequency of the vehicle sound per km/h of acceleration to ensure that pedestrians would be able to determine whether an [electric vehicle] is accelerating or decelerating.’

The proposed regulations will require carmakers to include ‘a dynamic range speaker system that is protected from the elements and attached with mounting hardware and wiring to both power the speaker and receive signal inputs and a digital signal processor that receives information from the vehicle regarding vehicle operating status (to produce sounds dependent upon vehicle status). ‘

Image by elPadawan.

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