New laws could mean noise for silent electric cars

Electric cars are quiet.

Perhaps that's a statement of the obvious, but for many owners, it's one of their cars' best features. Little noise, a smooth drivetrain, low running costs, environmental responsibility--it all adds up to an appealing package.

Regulatory bodies seem to feel electric cars are a little too quiet, though, posing a danger to pedestrians. As a result, several are in the process of drawing up legislation that will require car companies to add noisemakers to electric vehicles--to warn those around them who expect a vehicle to be audible of their presence.

But if one thing is truly quiet right now, it's news of any changes to the quiet-car noise requirement proposals from the U.S. National Highway Traffic Safety Administration (NHTSA).

In fact, the Department of Transport's safety body still hasn't convened with manufacturers to decide on noise-making regulations, since the proposals this time last year.

Back in March, an industry group of automakers countered the NHTSA's proposals, suggesting that the decibel level and tone of sounds emitted by electric and hybrid vehicles was set so high that even some gasoline sports cars would be quieter.

The NHTSA had suggested electric cars should produce a sound up to 18.6 mph, and even published a list of possible sounds at different volumes.

Automakers claimed the proposed sounds were too loud, and that most of a vehicle's noise above 12 mph is generated by tire roar anyway. Loud sounds would intrude into the passenger cabin, they said, above and beyond alerting pedestrians.

Automakers also took issue with the cost, suggesting the NHTSA's stated per-car cost of $35 was about one-fifth the real-world cost of development and production.

But the legislative debate is far from simply a U.S. problem.

In November, one U.K. politician also proposed noisemaking rules for electric and hybrid vehicles, citing statistics that electric and hybrid vehicle pedestrian collisions were 25 percent higher than the vehicle norm.

We suspected the figures may not tell the whole story, and as yet, there's been little proper study of the issue or conclusive evidence that quiet vehicles are any more dangerous than regular ones--a debate that's sure to rumble (quietly) on.

Back in the U.S, the NHTSA's proposals aren't set to come into force until September.

But even that deadline looks unlikely, given manufacturer opposition--and the fact that no further details have been released since then. If automakers have their way, such noisemaking rules could be pushed even further back--as far as 2018.

It's worth noting that many automakers have explored noisemaking devices without need for legislation.

Daimler recently said it's developing several electric-car tones for use in vehicles like the Smart Fortwo Electric Drive. That means everything from a "sonorous purring" for the Smart, to "huskier tones" in the SLS Electric Drive supercar, according to Bloomberg.

Renault too offers noise options for its Zoe electric subcompact, and Nissan's Leaf has been developed with a low-output sound, emitted below certain speeds.

Bloomberg also quotes Tesla CEO Elon Musk, who believes that electric cars should emit a "pleasant-sounding noise" at lower speeds, but only when pedestrians are around--at other times, the car should be silent.

In the end, accepted practices for pedestrian-alert noises in electric cars may come from the automakers themselves, without the need for legislation.

And that's probably the way it should be--but we're not holding our breath.