Electric Car Noise Generators Don't Work in the Real World

But as we’ve illustrated in the past, we’re not entirely convinced that forcing electric cars to make a noise at low speed is really that much of a help to pedestrians in the real world. 

Real Life Guinea-Pig

With that in mind, we set about conducting a series of completely tests with the aid of a partially sighted pedestrian who we accosted on the street and was only too happy to oblige in the interests of science. 

Partially sighted but registered blind, our test pedestrian used a cane and told us her sight was little more than an ability to see shades and shapes at close range. 

Would she be able to hear our approaching car, complete with audible alert?

The Unscientific Test

Lotus Safe & Sound noisemaker

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Approaching from the same direction each time in our test car, a 2011 Nissan Leaf, we made multiple passes on a quiet residential street at 15 miles per hour. 

In each case we could see our pedestrian raise a hand to signal she could hear the car approaching, but not until we were within a few feet of her - undeniably too short a time for evasive action. 

The Verdict

Our test subject didn’t know about the Leaf, nor did she know what to listen for. Once we’d explained, she could pick out the audible tone of the Leaf’s on-board Approaching Vehicle Sound for Pedestrians (VSP), but commented that it was too quiet to notice in anything other than a completely quiet street. 

Blind pedestrian accidents and fatalities per trillion vehicle miles traveled 1994-2008, NHTSA data

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In fact, on one occasion, she misheard the whine of the car’s electric motor as the VSP system when we’d turned it off - a brutal indication that the system not only works, but makes no difference in the real world. 

“The Leaf is much quieter than any other car on the road regardless of the noise generator” our test-subject told us. “I’d never be able to hear the sound in a town or city.”

But perhaps the most brutal comment from our partially sighted assistant comes from her conclusion of the whole exercise. 

“I thought it was the driver’s job to spot me? That’s why my stick is white”. 

It confirmed everything we’d thought up to that point. The use of VSP systems in electric cars is nothing more than an insurance policy against litigious pedestrians suing distracted drivers. 

Case closed.