Originally Posted by reply

Dear Editor,

It is never pleasant to criticize someone in public but sad to say, Jennifer Anderson's article "Researchers Want Engine Noise Added to Too-Quite Hybrids", January 25, 2009 is based upon an out of date press release, November 14, 2008 "Hybrid Cars Too Quiet for Pedestrian Safety? Add Engine Noise, Say Human Factors Researchers" by the Human Factors and Ergonomics Society. Worse, this press release is based upon a flawed paper "On Adding Sound to Quiet Vehicles" by Patrick Nyeste and Michael S. Wogalter of the Psychology Department, North Carolina State University. But sad to say, that is the case.

With the new Congress in January 2009, all legislation in committee died including "The Pedestrian Safety Enhancement Act of 2008, which would require the Secretary of Transportation to study and implement regulations for hybrid, electric, and other silent-engine vehicles to emit nonvisual alerts for pedestrians, is under consideration in the United States Congress." (Jennifer Anderson.) The specific legislation, H.R. 5734 needed to die in committee because there is no evidence in the National Highway Safety Administration databases of a higher hazard from the over 500,000 Prius that have been on USA streets and highways starting in 2001. More about this later.

The Press release from the Human Factors and Ergonomic Society dated November 14, 2008 was accurate about the legislation that was in committee. But it died with the new Congress. Sad to say, this press release is based upon a terribly flawed paper by Patrick Nyeste and Michael S. Wogalter.

In the second paragraph, Nyeste and Wogalter claim:

". . . One problem is the potential negative influence on pedestrian and bicyclist safety (e.g., Huppert, 2008). . . ."

Their source, Huppert, is a news report by the mother of an 8 year old boy who rode his bicycle into the path of a Prius. At best, this is an anecdotal story from a biased party to a single incident. Sad to say, this is just one element that claims there is a hybrid hazard. But had Nyster and Wogalter done proper research, they would have attended or even looked at the record from June 23, 2008 hearing by the National Highway Safety Administration (NHTSA):

www.regulations.gov - search NHTSA-2008-0108-0020 opposition research

They would have found "Analysis of Blind Pedestrian Deaths and Injuries from Motor Vehicle Crashes, 2002-2006" by Dr. Christopher Hogan. A professional research analyst in Vienna Virginia and Prius owner, Dr. Hogan looked at the NHTSA Fatality Accident Reporting System data covering all pedestrian fatalities 2002-2006 since the Prius has been on USA roads. From Dr. Hogan's summary:

"Counts and rates of death and injuries.
• From 2002 to 2006, on average, five legally blind pedestrians per year were killed in motor vehicle accidents in the US (Table 1).
. . .

Hybrids and pedestrian deaths.
• Over this period, no deaths of legally blind pedestrians involved a Prius (Table 3) or any other hybrid vehicle (Table 4).
• For all US pedestrian deaths (blind and sighted), 11 deaths involved a Prius (Table 3). (The Prius was singled out here because it is the only model with large production volume that was produced solely as a hybrid.) The Prius was no more likely to be involved in a pedestrian death than the average passenger vehicle (Table 5), accounting for 0.05 percent of registered vehicles and pedestrian deaths over this period.

Causes of blind pedestrian deaths.
• Over this period, pickup trucks were the vehicles most commonly involved in a blind pedestrian death (Table 3).
. . ."

A lot of things were going on in 2008 but to neglect an NHTSA hearing on "Quiet Cars" and analysis of directly relevant traffic accident data is a fundamental error. But this was compounded by use a single incident of a mother claiming her son's poor bicycling was cause not by her failure to teach him to look stretches the bounds credibility. A single poor reference does not condemn all of the Nyster, Wogalther paper but it means the rest of the paper and especially these inflated claims of a hazard need a closer look by serious people.

Robert J. Wilson
625k Inc.
Huntsville, AL