Electric and hybrid vehicles are known for the silent operation of its electric motors. To help make pedestrians aware of the approach of these kinds of vehicles, the United States' Department of Transportation's National Highway Traffic Safety Administration (NHTSA) is proposing that hybrid and electric vehicles meet minimum sound standards.
"Safety is our highest priority, and this proposal will help keep everyone using our nation's streets and roadways safe, whether they are motorists, bicyclists or pedestrians, and especially the blind and visually impaired," said US transportation secretary Ray LaHood.
Based on the NHTSA's proposal, the sounds should be detectable under a wide range of street noises and other ambient background sounds when the vehicle is traveling under 30kph. At over 30kph, the vehicles should make sufficient noise that would allow pedestrians and bicyclists to detect them without added sound.
In addition, though each carmaker would have a significant range of sounds to choose from for its vehicles, the characteristics of those sounds would need to meet certain minimum requirements. Also, each vehicle of the same make and model would need to emit the same sound or set of sounds.
"Our proposal would allow manufacturers the flexibility to design different sounds for different makes and models while still providing an opportunity for pedestrians, bicyclists and the visually impaired to detect and recognize a vehicle and make a decision about whether it is safe to cross the street," said NHTSA administrator David Strickland.