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Spokane, Washington  Est. May 19, 1883


Too quiet for comfort

The National Highway Traffic Safety Administration wants electric vehicles to make their presence better known.  According to safety experts, electric cars, and hybrids running in the electric mode, emit too-few decibels; in fact, the sound output of these vehicles is virtually nonexistent, making them a potential hazard to unwary pedestrians. 

The high-pitched “whirr” of an electric engine is difficult for many people to hear and impossible for others.  To become adequately audible, the NHTSA proposes the addition of a noise-making device on every such vehicle so that their presence is “announced” during slow-speed operation.

Under the Pedestrian Safety Enhancement Act, passed in 2010, the NHTSA is required to issue a formal ruling on the topic by 2014.  In January of this year, they announced their intent to require addition of noisemakers to electric and hybrid vehicles.  The agency is expected to issue a ruling after compiling public comment for 60 days, so an ahead-of-schedule decision is imminent.

Currently, September 2015 is being suggested as a start date for the requirement.  That would allow the typical advance warning to manufacturers for such rulings to become effective, giving them at least two years to ready the parts, assembly, etc.

Apparently, travelling over 18 mph, these cars produce sufficient noise from rolling tires and cutting through the wind to be heard by pedestrians.  But under that threshold of speed, supplemental noise is proposed to get the attention of those on foot.

The National Federation of the Blind is among the groups calling for the noisemakers.  For those who can’t see, hearing vehicles is an important element of pedestrian safety.  People with full operation of their senses can shift their vehicle awareness to sight, but those without sight would certainly benefit from the audible assistance.  A vehicle’s sound, since it is what we are accustomed to, is an additional cue our senses rely on to detect motor vehicles, and would likely be an unconscious aid to help anyone notice electric cars.

The NHTSA estimates a potential of 2,800 annual injuries could be prevented by the mandate.  At least the proposed noisemakers are not too expensive; it’s thought that the addition of the device on a given vehicle would only raise the price by about $35.

And what do you suppose the emitted noise should be?  Hopefully, not the reverse beepers we’ve all heard on trucks and construction rigs.  Automakers will be able to choose sounds from a range of choices; the government specifies that pedestrians must be able to hear the sounds over background noises.

I don’t think we want disruptive sounds like a mufflerless V-twin motorcycle; I also have no desire to hear a Nissan Leaf that “shows” itself via the clatter of a one-ton diesel-powered truck.  At their Website, the NHTSA has WAV recordings of various sounds made by typical gasoline-powered vehicles; essentially, most of them sound like an amplified version of the “ocean” roar heard when placing a seashell to one’s ear.

Undoubtedly, some manufacturers will give vehicle owners a “dial-a-sound” option.  That way, depending on mood, drivers could dial up 4, 6, or 8 cylinder sounds, with or without performance exhaust.  Why stop there?  A horsepower-deprived operator might be able to replicate the sound of a Formula One racecar for a temporary, vicarious thrill.  To get instant attention, how about the tunes played by an ice cream vendor’s truck?

Actually, sounds will simulate the vehicle noises we are already used to hearing.  Conventional gasoline powered vehicle engine noise provides lots of information to pedestrians, such as whether or not the vehicle is idling, accelerating, braking, and moving away or toward you.  Therefore, any artificial sound added to cars should to be able to do the same. 

Whatever the sounds are, they’ll help curtail the vehicle/pedestrian mishaps that have been on the rise as the electric vehicle population grows.  The noise proposal will almost certainly be adopted, since it has backing within the automotive industry by groups such as the Association of International Automobile Manufacturers and the Alliance of Automobile Manufacturers.  Those endorsements, along with a push from vision-impaired support organizations and consumer safety organizations,will be influential.

Readers may contact Bill Love via e-mail at