Electric vehicles and hybrid cars could be required to sound alerts to pedestrians under a new proposal from the National Highway Traffic Safety Administration.
In a notice posted yesterday on its website, the agency announced the first steps toward a rule aimed at protecting pedestrians and bikers from the nearly silent cars.
The regulation would force light-duty cars, motorcycles, vans and trucks to automatically sound alerts at low speeds.
"Even as we make giant leaps forward with hybrid and electric vehicles, we must remain laser focused on safety," NHTSA Administrator David Strickland said in a statement. "With more and more quiet vehicles on the road, we have to consider their effect on pedestrians."
The move was mandated under the Pedestrian Safety Enhancement Act of 2010, which calls for NHTSA to publish a final rule requiring alerts and setting standards for them by January 2014. The standards would take effect within three years of the final rule's publication.
Two previous administration reports on the matter found that the quiet hybrid and electric vehicles posed a greater safety risk than their gas-powered equivalents, particularly to visually impaired pedestrians.
The Chevrolet Volt already has a warning system for pedestrians, although drivers must activate that system.
Japan requires its automakers to install sound alerts, and the Nissan Leaf emits an engine noise at low speeds and has a chirp when the car is in reverse.
The NHTSA notice says the agency will explore several options, including a synthetic sound, a system that mimics the noise of an internal combustion engine at low speeds or a combination of the two.
The notice will be published soon in the Federal Register, opening a 30-day comment period.