WASHINGTON - The age of the silent hybrid may be coming to an end.
Gas-electric hybrids, propelled by electric motors at low speeds, are well-known for their quiet ride and great mileage. But their silence isn't always golden.
Some researchers and safety groups say that quiet operation, "hybrid creep," can pose risks for unsuspecting pedestrians and the blind, who use sound cues.
Advocates for the blind have sought the addition of artificial noises in hybrids for several years, concerned that the expected sales growth of hybrids could lead to more pedestrian fatalities and injuries. Hybrids account for about 2 percent of new car sales each year but auto companies are expected to boost production in advance of tougher fuel efficiency standards this decade.
"This is an example of too much of a good thing," said John Pare, executive director for strategic initiatives with the National Federation of the Blind. "Cars got quieter, that was good. Suddenly they got to be so quiet that it added an element of danger."
The government's auto safety agency said in a research report last year that hybrid vehicles are twice as likely to be involved in pedestrian crashes at low speeds, compared with cars with conventional engines.
Congress is heeding the warnings, adding sound performance requirements for hybrids and electric cars to an auto safety bill being considered after the massive Toyota recalls. Lawmakers could consider the changes this summer and car companies are most likely to have to have the sounds ready to go three years after the release of new government rules.
Automakers helped develop the proposal in Congress and are moving forward with artificial sounds to be emitted from electric cars and hybrid models.
Some green car advocates have questioned the need for the extra tones and noted that the requirement could add more noise to neighborhoods. Paul Scott, vice president of Plug In America, said the sounds could help under certain circumstances, but drivers should have the right to activate the tones.