Without the quiet, subtle rumble of an idling engine, EVs and hybrids can be near-silent when rolling around at low speed. Newer models have special low-speed noisemakers built-in to protect pedestrians—especially children and blind people—but these only became mandatory in recent years. The NHTSA is now considering whether older vehicles should be required to retrofit pedestrian warning devices.
As reported by Teslarati, the NHTSA opened an investigation into the matter on Jan. 27, 2023. The matter came to the agency's attention via a petition submitted on July 18 last year. The petitioner asserted that the agency should consider older hybrids and EVs without noisemakers to be defective, regardless if they were originally legally sold without them. The submission to the NHTSA cites the Pedestrian Safety Enhancement Act of 2010, which directed the Secretary of Transportation to develop a "safety standard that provides for a means of alerting blind and other pedestrians of motor vehicle operation."
When it comes to pedestrian noisemakers on vehicles, the relevant piece of legislation is the Federal Motor Vehicle Safety Standard 141. The standard requires that all hybrids and EVs under 10,000 pounds produce sounds when traveling at speeds up to 18 mph. The intention of the requirement was to improve pedestrian safety, particularly for the blind and visually impaired. By ensuring that EVs and hybrids made a minimum level of noise, it would help pedestrians stay aware of vehicles moving in their vicinity, particularly in areas like parking lots and shared spaces.
The requirements of FMVSS 141 became mandatory for vehicles built on or after March 1, 2021. That leaves millions of electrified vehicles in the U.S. which were built without pedestrian noisemakers.
The NHTSA has prepared a non-exhaustive list of affected vehicles with the oldest models dating back to 1997. It goes all the way back to early EVs like the Saturn EV1 from 1997, as well as the first U.S. models of the Honda Insight and Toyota Prius from 2001. Beyond that, the list covers a broad range of electric and hybrid vehicles built in the last two decades, from the Nissan Leaf to the Malibu Hybrid. It even includes the Ferrari LaFerrari and SF90 Stradale, as both models feature hybrid drivetrains. The NHTSA notes that some vehicles on the list may already be fitted with appropriate noisemakers from the factory.
Retrofitting noisemakers should not be excessively difficult if required by the NHTSA. To avoid the noisemakers being on all the time, they will require access to the vehicle's speed data. Automakers could likely develop plug-and-play kits for installation by dealers that capture speed data via the CAN bus. The difficulty of installation would vary by vehicle, but the fundamental concept is relatively straightforward.
Given the obvious safety risks of silent cars, it's perhaps surprising it took the NHTSA so long to mandate a minimum low-speed noise requirement. However, most jurisdictions have been similarly slow to act. The E.U. only required noisemakers to be fitted from 2019 onwards, for example.
It would be an unusual step for the NHTSA to require past vehicles to be retrofitted in this way. Laws on airbags and seatbelts, for example, were never applied retroactively to previously-built vehicles. For now, the agency is merely evaluating the petitioner's arguments, with a decision to come further down the line. If you run an automotive supplier that builds EV noisemakers, though, take note. It may be worth drawing up some plans for retrofit kits ahead of time.
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