Sounds to keep people safe from quiet vehicles

The United States government is introducing rules that require electric vehicles and hybrids to produce sounds at speeds of up to 30 kilometres per hour to help prevent injuries.

The rules aim to make it safer for pedestrians, cyclists and the blind and will require automakers to add alert sounds to all vehicles by September 2019, Reuters reports.

The US Transportation Department says it expects the rules would prevent 2400 injuries a year in 2020.

It would cost the auto industry about US$39 million (NZ$54.9 million) annually to make the changes because automakers need to add an external waterproof speakers to comply, the US National Highway Transportation Department says.

But the benefits of the reduced injuries are estimated at US$250 million to US$320 million annually.

At higher speeds, the sound alert is not required because other factors like tyre and wind noise provide adequate warning to pedestrians, NHTSA says.