Accident Reconstruction Network > News >June 2008

Accident Reconstruction News Article

By Joe Benton
ConsumerAffairs.com

The National Highway Traffic Safety Administration (NHTSA) plans a day of public hearings to look at the dangers quiet-running hybrid vehicles pose for visually impaired pedestrians and bicyclists.

Four states and the U.S. Congress are considering legislation to set minimum sound levels as a warning for pedestrians of an approaching hybrid running on electric power only.

The Pedestrian Safety Enhancement Act of 2008 proposes a two-year study to determine the most practical way for hybrid and electrical vehicles to provide non-visual cues for pedestrians.

The National Federation of the Blind, with 50,000 members, will speak at the NHTSA hearing. The Federation advocates a minimum sound standard for all new vehicles sold and licensed in the U.S.

A child in Minneapolis was hit in May by a Toyota Prius that the 8-year-old bicyclist did not hear. The child was not seriously injured.

The Federation of the Blind has reported several close calls invovling blind pedestrians and hybrids.

Six blind pedestrians were killed by moving vehicles in 2007, according to NHTSA. None of the vehicles involved was a hybrid, according to the agency.

At low speeds, particularly near intersections, the gasoline-powered engine in a hybrid may shut down, eliminating most of the noise coming from the car.

Hybrid sales rising

Hybrid sales are increasing. They were up 38 percent in 2007 to 350,000 vehicles and are running ahead of that pace this year. The risk of stepping in front of a silent-running hybrid is likely to be on the rise.

A University of California study by Lawrence Rosenblum, an adviser to SAE International which is an association of automotive engineers, concludes that hybrids operating at 5 mph need to be 74 percent closer than a conventional vehicle before they make enough noise for their location to be heard.

Above 20 or 25 miles an hour, hybrid or electric car tires make enough noise for people to hear them.

A California start-up company, Enhanced Vehicle Acoustics, is developing a system called the Pedestrian Awareness Noise-Emitting Device and Application.

The system puts a small speaker near each front wheel of a hybrid and emits the sound of an internal combustion engine to warn pedestrians. The system requires no more power than a car radio and shuts off at speeds above 25 mph.

Called PANDA by its developers, the system "allows drivers, companies or municipalities to potentially establish their own external automobile sound identities, all within a recognizable and respectful soundscape," according to the company.

Now what sound should a Prius make while slowly passing a Hummer?

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