If the NHTSA has its way, quiet motorcycles will be banned! To be more specific, electric vehicles of all types, including two wheelers, are frequently so quiet that they pose a safety risk to pedestrians at low speeds. Here is how the NHTSA puts it:
Whether or not a vehicle can be easily detected by the sound it makes is a product of vehicle type, vehicle speed, and ambient sound level. Quieter vehicles, such as EVs and HVs, can reduce pedestrians’ ability to assess the state of nearby traffic and, as a result, can have an impact on pedestrian safety. EVs and HVs may pose a safety problem for pedestrians, in particular pedestrians who are blind or visually impaired and who therefore rely on auditory cues from vehicles to navigate. For these pedestrians, the primary safety issue arises when an HV or EV operates quietly using its electric motor for propulsion at low speeds. This is also the case when other auditory cues, such as the noise from the vehicle’s tires and wind resistance, are less noticeable.
The irony of the government attempting to mandate more noise from motorcycles is hard to overlook, but the low speed menace of electric vehicles is real. You can read the NHTSA’s full analysis by opening this PDF. You can also listen to a sampling of recordings suggested by the NHTSA for use on electric vehicles when traveling at low speeds here. As usual, the Europeans are way out in front of us on this issue, as evidenced by the video below.