WASHINGTON — Electric cars, which have soundless engines, would need to make noises to let pedestrians know they’re near under a U.S. proposed rule released Monday.
Sounds would need to be detectable when vehicles are traveling slower than 18 mph (29 kilometers) so electric and hybrid-electric cars can be heard by bicyclists and pedestrians, particularly the visually impaired, under the U.S. National Highway Traffic Safety Administration rule.
The so-called quiet-car rule, which would have to be made final before it takes effect, would save 35 lives over each model year of hybrid vehicles and prevent 2,800 injuries, the agency said in an emailed statement.
“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,” NHTSA Administrator David Strickland said in the statement.
Adding external speakers to quiet vehicles would cost about $25 million a year, or about $35 per light vehicle, NHTSA said. About $1.48 million of the annual costs would be to equip large trucks and buses and motorcycles with sound, the agency said.
That cost compares with $2.7 billion a year for a rule NHTSA failed to issue by its deadline last week to require backup cameras in all new cars. Both rules were required by laws passed by Congress.
The quiet-car rule’s cost assumes hybrid vehicles are 4.1 percent of U.S. light-vehicle sales.
The National Federation of the Blind had pushed for the rule, saying an increasing number of cars that don’t make noise at low speeds puts blind people at risk.
Above 18 mph, cars make enough noise that they don’t need artificial sound, NHTSA said. Hybrid-electric cars such as General Motors’s Chevrolet Volt use electric engines at low speeds and can switch to internal-combustion engines. Fully electric cars such as the Nissan Leaf use only battery power.
Cars that aren’t using internal-combustion engines don’t make noise while they accelerate or idle like vehicles that are powered by gasoline or diesel fuel. The Pedestrian Safety Enhancement Act of 2010 requires the U.S. Transportation Department, which includes NHTSA, to write a rule addressing this issue by Jan. 4, 2014.
Quiet cars are twice as likely as vehicles with internal-combustion engines to be involved in pedestrian crashes when backing up, slowing or stopping, starting in traffic or entering or leaving a parking space or driveway, NHTSA said in a 2011 study.