Safety Agency Proposes Sound Requirements for Green Cars

U.S. auto safety regulators are proposing sound requirements for green cars that would make such vehicles easier to detect when they are traveling below 18 miles an hour, the National Highway Traffic Safety Administration said on Monday.

Such a rule would prevent accidents and injuries, particularly among pedestrians, bicyclists and those who are visually impaired, the NHTSA said in a news release.

Electric and hybrids vehicles do not rely on gas- or diesel-powered engines at speeds below 18 miles an hour, which makes them much quieter than mainstream cars.

Under the rule proposed by the NHTSA, such vehicles would have to emit a sound at low speeds that alerts others to their presence. The sound must be loud enough to be heard above street noise and other ambient background noise.