Electric vehicle warning sounds

Electric vehicle warning sounds are sounds designed to alert pedestrians to the presence of electric drive vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs) travelling at low speeds. Warning sound devices were deemed necessary by some government regulators because vehicles operating in all-electric mode produce less noise than traditional combustion engine vehicles and can make it difficult for pedestrians and cyclists to be aware of their presence. This is a particular problem for those with visual impairments. Warning sounds may be activated by the driver (similar to a horn) or turn on automatically at low speeds. These sounds vary from clearly artificial (such as beeps and chimes) to those that mimic engine sounds or tires rolling over gravel.

Japan issued guidelines for such warning devices in January 2010, and the US approved legislation in December 2010. The US National Highway Traffic Safety Administration issued its final ruling in February 2018. Their ruling requires vehicles to emit warning sounds at speeds below 18.6 mph (30 km/h), with full compliance by September 2020 and 50% of "quiet" vehicles compliant by September 2019. In April 2014, the European Parliament approved legislation that requires the mandatory use of an acoustic vehicle alerting system (AVAS). Manufacturers must install an AVAS in four-wheeled electric and hybrid electric vehicles that are approved from July 1, 2019, and in all new quiet electric and hybrid vehicles registered from July 2021.