If you’ve ever ridden in a hybrid car, I’m sure you’ve noticed the peculiar silence when the engine starts, and the way it simply “rolls” onto the road ““ but are hybrids too quiet for their own good? Some pedestrians, and particularly blind pedestrians, say that they are.

Jana Littrel, who is blind, had her foot run over by a Toyota Prius while walking through a bank parking lot in the East Bay town of Albany a year ago. Although she managed to avoid injury, Jana says the incident has put her on edge. So far, no deaths or serious injuries have been attributed to hybrids. Still, The National Federation for the Blind is currently working toward getting hybrid automobile manufacturers to install a “noise emitting device” so that blind pedestrians, as well as joggers, children, animals, and cyclists can be made aware of the oncoming vehicle.

One problem has been in isolating exactly what sounds most people associate with an approaching vehicle, such as the engine revving, the fan belt, tire noise or other sounds. Artificial warning cues “like chirping or chimes are not identified by test subjects as a vehicle at all,” the automaker said.

Interim solutions include training guide dogs for the blind to detect cars by sight as well as sound. Training schools such as Guide Dogs for the Blind in San Rafael and Guide Dogs of the Desert near Palm Springs have added Priuses to their training regimens partly in response to concerns about hybrid cars.

It’s an ironic twist to the increasing popularity of these eco-friendly vehicles. The cars may be quiet, but the demand for them is getting noisier. 350,000 hybrid cars were sold last year the US alone ““ that’s a 100% increase in the US purchase of hybrid vehicles since 2006. Yet a subsequent result is the rising concern about the potential negative impact these quiet-running cars could have on the road.

Want to know more? and peruse a variety of topics concerning hybrid vehicles on the greenhybrid.com forum, including the one discussed above. You can also check out this YouTube video below of a blind pedestrian expressing her concerns about hybrid cars.