WASHINGTON -- A plan to make electric cars louder in the name of safety could annoy drivers and inhibit adoption of electric vehicle technology, automakers say.
The National Highway Traffic Safety Administration proposed rules for quiet cars in January, in line with a 2010 law passed at the urging of advocates for the blind. Adding speaker systems to alert pedestrians would increase the cost of an EV or hybrid by an estimated $35, but that's not the main worry for car companies.
In comments prepared to be filed with NHTSA before last week's deadline, the Alliance of Automobile Manufacturers and several individual car companies said that the noises could irritate drivers and the public if done the wrong way. Some automakers also said there is no need for EVs and hybrids to play sounds while motionless since it is not clear that it helps pedestrians to hear cars that are stopped in traffic or parked.
A louder or more unpleasant sound "causes lower acceptance among pedestrians and drivers," five makers of EVs and hybrids -- Nissan, General Motors, Toyota, Honda and Mitsubishi -- told NHTSA officials during a presentation on Feb. 21.
Most of the EVs and hybrids sold today make noises using a speaker system, in anticipation of a NHTSA rule. Among the suppliers is Delphi Automotive, which sells a box containing a microprocessor and amplifier that can be mounted under the hood.
Automakers generally have not opted to play sounds while a car is not moving. The system used in the Mitsubishi i-MiEV, for example, cuts off when a driver brakes to below 2 mph or shifts into park.
For the Feb. 21 meeting, the automakers brought their EVs to NHTSA's Washington headquarters and drove around the neighborhood. Representatives of the National Federation of the Blind also attended.
During the meeting, the automakers tried to show that sounds from stationary cars would make neighborhoods noisier.
And when it comes to safety, they said, having stationary cars make noise could backfire by masking the sound of approaching cars or making it difficult to tell when an EV or hybrid has started moving.
For now, the NHTSA rules would barely change the sonic environment on American roadways. Automakers sold a few more than 50,000 plug-in hybrids and EVs in the United States last year, or about 0.4 percent of all cars sold.
But automakers want to sell more battery-powered cars in the years ahead, and they worry that annoying noises would complicate marketing efforts.
Automakers often tout their EVs and hybrids as being virtually silent at low speeds. In some cases, sounds meant to warn pedestrians can be heard by passengers as well.
"It's a tough thing," said Timothy Mellon, director of government affairs at SAE International, which came up with the protocol for testing noise from cars. "In surveys, one of the big indicators of quality has always been the lack of sound in the passenger compartment of a car."