Skip to Content

Hear the GM Volt Warning for the Blind

Electric vehicles could sneak up on pedestrians; a warning system could head off lawsuits.
November 30, 2009

One of the great selling points of electric vehicles is that they’re much quieter than conventional cars. But this can pose a problem for pedestrians, particularly blind ones. This is particularly true at low speeds, when there’s not much noise coming from the tires or from air rushing around the car. When a car passes slowly in a parking garage or backs out of a driveway, pedestrians can hear the engine in a conventional car, but not the quiet electric motors in electric cars.

As a result, in the last couple of years the National Federation for the Blind has been lobbying for legislation that would require such cars to emit some sort of audible warning. Now the NFB has teamed up with GM to help develop such as system for the Volt, an electric vehicle with a back-up gasoline engine for extending driving range. Representatives from the federation recently took a trip to visit the Volt to evaluate the system so far–you can see a video of the meeting here, and hear the prototype warning sound. It’s an electronically modulated version of one of the Volt’s two horns. “We don’t want it to be startling,” says Andrew Farah, the Volt’s Chief Engineer. “We want it to be more of a pleasant sound.” He says, it’s designed to sound like a gentle “excuse me” rather than a startling “hey you!”

At the meeting, one of the representatives of the NFB declared that the system was a good one, provided it gets used. Chances are, however, that the system will almost never get used. The sound isn’t automatic, something that engages at low speeds. It has to be activated by the driver. The idea is that if you find yourself driving along quietly at low speeds, you’ll flip a switch, and the horn will start clearing its throat–a sound that right now is pretty obnoxious. As an added safety bonus, your lights will also flash. I can imagine that a few well-intentioned individuals will use the feature on the first few times out. But after a little of the grating noise, they’ll switch it off.

Basically, the system seems like a way for GM to fend off lawsuits, to pass the responsibility on to drivers. It’s not going to do much to save pedestrians. But an automatic system isn’t good either. I certainly wouldn’t want to buy an electric vehicle that always makes annoying sounds at low speeds. And any sound distinctive enough to serve as a warning would be annoying.

Maybe a system that detects pedestrians and only then sends out a warning would be better. Or one that automatically applies the brakes, in case the driver isn’t paying attention. Systems already exist, but they detect cars rather than pedestrians. Such systems, however, would undoubtedly be expensive, and electric vehicles are expensive enough as it is.

I’m inclined to think the best approach is to hold drivers responsible for watching out for pedestrians. Any better ideas?

Keep Reading

Most Popular

Rendering of Waterfront Toronto project
Rendering of Waterfront Toronto project

Toronto wants to kill the smart city forever

The city wants to get right what Sidewalk Labs got so wrong.

Muhammad bin Salman funds anti-aging research
Muhammad bin Salman funds anti-aging research

Saudi Arabia plans to spend $1 billion a year discovering treatments to slow aging

The oil kingdom fears that its population is aging at an accelerated rate and hopes to test drugs to reverse the problem. First up might be the diabetes drug metformin.

Yann LeCun
Yann LeCun

Yann LeCun has a bold new vision for the future of AI

One of the godfathers of deep learning pulls together old ideas to sketch out a fresh path for AI, but raises as many questions as he answers.

images created by Google Imagen
images created by Google Imagen

The dark secret behind those cute AI-generated animal images

Google Brain has revealed its own image-making AI, called Imagen. But don't expect to see anything that isn't wholesome.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at with a list of newsletters you’d like to receive.