One of the qualities that makes an electric car so appealing to drivers also makes it a deadly danger to pedestrians. An electric vehicle makes very little noise, so blind pedestrians or people in noisy areas will never hear the silent car coming their way. So Norway wants all such cars to make enough noise to be heard.
The Scandinavian country is planning to require existing and future electric cars to emit a distinct sound that can be heard over the din of normal traffic. The sound will warn pedestrians who are distracted or unable to see the approaching vehicle.
“An electric car must emit an artificially produced sound of varying frequency but fairly constant intensity when travelling at 20 km/h or less,” SINTEF researcher Truls Berge said regarding the planned requirements.
Norway is just one of the many countries that plan to impose these new safety requirements. These laws are long overdue.
As of a 2018 report by GEVO, there are now more than three million electric vehicles of all kinds on the roads. And while Norway does not have the largest number of such vehicles, it does have the highest density of electric cars. (Related: Electric vehicles to become more affordable than gas guzzling counterparts in just 7 years: Report.)
Berge is an expert on the sounds and noises made by motor vehicles. He is well aware of the problems and complications connected to those vehicular noises – or the lack of such noises in electric vehicles.
He welcomes Norway’s plan to impose sound requirements on electric vehicles as a step in the right direction toward protecting blind pedestrians. However, he also believes that the plan failed to take certain things into consideration, such as existing noise levels and ongoing attempts to reduce noise pollution.
“The new requirements do not take into account the environment in which a vehicle is operating,” Berge pointed out. “There is a big difference between the sound needed in a street on a peaceful evening and in a busy urban traffic environment.”
Conventional vehicular traffic makes a lot of noise. When combined with the loud sounds in an urban environment, this could result in noise pollution that causes health problems.
Berge says that Norway and other countries must strike a balancing act between ensuring the safety of blind and visually impaired pedestrians and maintaining their efforts at reducing noise pollution.
Along with other SINTEF researchers, Berge demonstrated a potential solution to the problem posed by silent electric cars: an “adaptive sound” system.
In their concept, an electric vehicle will receive a suite of microphones that can determine the ambient sound level outside the vehicle. It would then issue an appropriately loud sound that could be heard by blind or visually impaired people.
The Norwegian researchers tested their concept with the help of blind volunteers. They set up loudspeakers that emitted sound levels similar to the ambient sound in a typical urban street.
The modified electric car would issue a warning sound. If the blind participants heard the sound despite the ambient sound levels, they would indicate it by pushing a button.
The results of the test helped the researchers figure out the distances at which pedestrians heard the adaptive warning sound issued by the car. Berge expresses his hope that automobile companies like Nissan, General Motors, and Renault will make good use of his findings.