To improve safety on its busy streets, London is set to trial an audio track on its hybrid and electric buses that will automatically play on external speakers when the vehicle is stationary or traveling at a slow speed.
With electric vehicles making little noise due to the absence of a combustion engine, the audio will alert nearby pedestrians, cyclists, and the visually impaired to the bus’s presence.
So what kind of sound are they testing? Well, don’t expect an artificial engine noise. Instead, the audio is somewhat soporific and definitely soothing, and could make for an interesting chorus in central London locations where lots of buses tend to gather together (like everywhere during rush hour).
Revealed by Wired to be the work of London-based Zelig Sound, the audio is designed to play until the electric bus reaches 12 mph (19.3 kph), at which point it will fade out as the vehicle starts to generate its own noise. The recorded sound will alter its pitch according to the bus’s speed, giving those nearby a better idea of its movement and position. It’ll also play when the vehicle reverses and comes to a halt at bus stops.
Transport for London (TfL), which is running the six-month trial, will also experiment with different volume levels to determine the most effective setting.
The trial starts in January and will use electric buses along at least three routes. The capital city currently operates 200 electric buses — the most among all European cities — in a total fleet of around 9,000. The introduction of the artificial bus sound is part of TfL’s Bus Safety Standard program that supports the mayor’s Vision Zero initiative aiming for zero deaths and serious injuries on London’s roads by 2041.
The sound test comes as the European Union begins to introduce rules that make an alert sound a necessity for electric vehicles traveling on European roads. But with the United Kingdom on course to leave the E.U., it remains to be seen whether the British government decides to retain the rule for its own roads.
A similar law to make electric vehicles noisier is also coming to the United States. The National Highway Traffic Safety Administration (NHTSA) will require all electric and hybrid vehicles to make a sound when traveling at speeds of up to 18.6 mph (30 kph).
Set to come into force in September 2020, the NHTSA is currently thinking about whether to let automakers offer different sounds, allowing the driver to choose between, for example, something engine-like or a piece of audio a little more unusual — like the one being trialed in London.
Automakers are already hard at work on researching different sounds for their electric cars. Tesla CEO Elon Musk certainly has some offbeat ideas for his company’s own vehicles, but knowing Musk as we do, we shouldn’t be so surprised.
