OK, I’ll admit it: On more than one occasion, I have put my beloved Toyota Prius into reverse and come uncomfortably close to running over a few bystanders. It wasn’t because I didn’t see them (I swear!) it’s because they didn’t see -- or, to be more precise, hear -- me. While operating on its electric battery, my car is silent as a shooting star, so the pedestrians waltzed right into my line of fire, having no audible warning that I was approaching.

As it turns out, I’m not alone: “As hybrid sales skyrocket, there's a growing concern that the battery-gas powered vehicles pose a risk because they aren't as noisy as gas-powered engines,” says a recent Mercury News article. “One of the dangerous drawbacks of driving a hybrid [is that] it's so quiet that pedestrians can't hear it when it's starting up or idling, and they often walk right into the path of the moving vehicle.”

As yet, there is no clear data revealing a more accidents among electric or hybrid-engine cars than conventional vehicles, but that could be because the former have only begun populating American highways in the past few years. Annual sales of hybrids in the United States are expected to increase more than 30 percent this year -- up to nearly 300,000.

Especially concerned about the trend is the National Federation of the Blind, which has asserted that electric cars and hybrids are particularly threatening to people who “see” with their ears when crossing a street. The group proposed that hybrids should be required to give off some sort of benign noise while on electric mode, perhaps by having the radiator fan switch on, to alert passersby.

As yet no such requirement has been implemented, and it's unclear if the problem will get worse as more clean, quiet-engine cars populate the roadways. But it is clear that one of the greatest blessings of having a hybrid-electric car – its incredibly peaceful engine – may also be a curse.

Photo credit: Toyota.com