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Perspectives and Issues on the Development of the Quiet Hybrid Automobile

Thursday, March 1, 2007

By: John Rae

President, Alliance for Equality of Blind Canadians /
L'Alliance pour l'ÉgalitÉ des Personnes Aveugles du Canada

PO Box 20262, RPO Town Centre
Kelowna, BC V1Y 9H2

A Paper to be Presented at the 11th International Conference on Mobility and Transport for Elderly and Disabled Persons (TRANSED), Montreal, Quebec, June, 2007

Pedestrian safety is of utmost importance to all members of the public who use city sidewalks, attempt to enter shopping malls, or cross busy intersections. It is also a basic human rights issue.

This paper is intended to increase awareness of the dangers of the quiet, hybrid automobile, foster dialogue among major stakeholders, and discuss several issues and possible solutions to this growing menace on our streets. The perspectives presented are drawn from a variety of sources, both personal communications and published sources.

My name is John Rae. I live in Toronto, Ontario, and have been blind for the majority of my 58 years. I navigate around Toronto on subways, buses, streetcars and on foot. I also travel regularly to other cities in Canada, and have visited 24 countries on five continents. Safe and independent travel is vitally important to me and all other pedestrians.

Today city streets are becoming increasingly dangerous for all pedestrians. There are more and more motorists; many are in a hurry in this fast-paced world; and many are distracted while talking on their cell phones. The presence of more and more quiet automobiles on our streets will only add to existing safety hazards throughout our communities.


"I encountered my first hybrid car when Jim, a family friend, dropped by one morning driving a brand-new Toyota Prius. He explained that the Prius uses electric power when running at speeds up to about twenty mph and periodically switches to electric power at faster speeds as well. He added that the car is extremely quiet in its electric mode--so silent, in fact, that car dealers have affectionately dubbed it a stealth vehicle.

Eager to prove to myself that I would be able to hear the Prius, no matter what the dealers boasted, I asked Jim to conduct an experiment. He agreed to take the Prius for a short test drive while I listened from the sidewalk in front of my house on a quiet side street. I heard him climb into the car and slam the door on the driver's side. Then I waited, listening for him to start the engine. Nothing happened. I heard only the sparrows chirping in the trees and the distant roar of a lawn mower. At last the car door opened again and Jim asked, "Could you hear it?"

"Hear what?" I demanded. "Why didn't you start up?"

"I did start up," he said. "I drove to the end of the block. Then I backed up and went about three houses past yours. Then I drove back and parked here in front of you again."

I went to the curb and rested my hand lightly on the passenger door. Again Jim started the engine. I felt the car move forward. Uncannily, eerily, it did not make a sound. With horror I realized that I could easily step straight into the path of an oncoming Prius with no hint of peril." {Stein, 2005}


A number of cars and pick-up trucks now operate using a combination of electricity and gasoline. These vehicles are known as hybrids because they blend combustion-engine and electric-motor technologies. Excess energy from the combustion-engine energy, which is wasted in conventional vehicles, charges the battery that runs the hybrid's electric motor. When it is in operation, the hybrid vehicle shifts automatically from one power mode to the other. How often and in what circumstances the vehicle uses electric power varies widely according to model and design. The engine is silent when operating in electric-power mode.

Some examples of hybrid autos are:

  • Lexus RX 400h hybrid
  • Lexus GS 450h Hybrid
  • Honda Civic Hybrid
  • Honda Accord Hybrid
  • Honda Insight Hybrid
  • Toyota Prius
  • 2007 Toyota Camry hybrid
  • Toyota Highlander
  • Ford Escape Hybrid

The following is an owner's perspective:

"I purchased a Toyota Prius in June, 2006. My decision to buy this particular car was primarily based on a desire to purchase a fuel efficient and well made vehicle which would withstand the long commutes to and from my job and still be an optimal choice environmentally. The Toyota Prius exceeds all of my expectations, and friends of mine have raved about how quiet it is. Many have remarked that had they not seen the car approaching, they wouldn't have known my car was coming toward them. This does bring up a concern for me, however. I have a sister who has been blind since birth.
Even before I purchased my car, she and I had spoken about the pros and cons of such hybrid cars and the dangers they pose to blind pedestrians because no sound is made by the Prius and other hybrid cars when they are stopped at intersections or when they begin to accelerate. My sister and I both believe that manufacturers of hybrid vehicles need to take concerns of blind pedestrians very seriously and have a responsibility to somehow make them emit some kind of sound when the engine is not engaged and the vehicle is running on electric power."
--Douglas Taube, Hayward, California

The following is a perspective from a concerned parent who is blind:

"I am particularly worried as I am a parent of boys 2 and 4 years old. I am often accessing the local community with them and I have to know that I am safe as I am responsible for them both. So it is always at the back of my mind that one of these days I will be confronted with these new types of cars. This new technology poses a new challenge to road safety and as a result access." {Bartlett, 2005}

For pedestrians who are blind or partially sighted, the issue isn't just being able to cross an intersection with confidence and in safety; it has wider implications for our overall mobility and independence.

The following illustrates how blind pedestrians evaluate various travel environments:

“Contrary to popular belief, our guide dogs do not read the traffic lights for us. When I reach a lighted intersection, I listen for the sound of traffic flow. If the traffic is flowing parallel to me, it means my light is green, and I can cross. If the intersection were full of quiet cars, I could not read the traffic and would not know when to give my dog the "forward" command.

When I stop at the corner of a stop street with no light, I listen to make sure no traffic is approaching before giving my dog the "forward" command. Again, if the intersection were filled with quiet vehicles, I would not know when it was safe to do this.

When I travel on a road with no sidewalks, I walk on the left-hand side with my dog on my left facing traffic. When cars approach us, I turn us into the curb edge to make sure we are out of the line of fire! Again, I would not know when traffic was approaching.

When walking through parking lots, I would not know if quiet cars were suddenly turning in front of me or coming from behind.

When walking down a sidewalk, I would not know if a quiet car was pulling into or out of a driveway.

Many of our big cities are now filled with wheelchair ramps at curbs. This is generally a good thing but makes lining up with an intersection trickier for someone who is blind. I use traffic noise to make sure I am pointing in the correct direction for a street crossing. This is especially useful when coming to rounded curbs, which make it even more difficult to line up with intersections.

In the winter here in Canada with snow-covered corners, lining up with intersections is trickier. When it is windy or raining hard or in winter when you need to wear a hat, traffic noise is already more muffled." {Kilpatrick, 2005}

We must all admit that automobiles are a major cause of the pollution that is endangering the health of our planet. Hybrid vehicles typically offer higher gas mileage, and lower engine exhaust emissions. Cleaner air and a reduction in greenhouse gases benefits our environment and everyone needs to support more environmentally friendly programs. However, as currently manufactured, the increasing prevalence of quiet hybrid vehicles on our roads creates new safety hazards for all pedestrians, especially individuals who are blind, partially sighted or who have reduced hearing.

"Who doesn't want to do something good for the environment including reducing noise pollution? How do we find the balance between noise pollution and the right of pedestrians to travel safely? In my books, pedestrian safety trumps driver comfort. Driving is a privilege, my safety is a right."
-- Linda Bartram, Victoria, BC

"I applaud the concept behind them. Anything that allows people to use less gasoline should be a good thing. However, these things are going to be death sentences for the blind and hard of hearing. I myself in addition to being blind am deaf in one ear with a mild to moderate hearing loss in the other and hearing aides do me no good. I have enough trouble crossing streets to begin with. It's gotten harder over the years as cars have gotten quieter by the year. The last thing we need is a car with no sound at all.

The streets are becoming more and more unsafe for blind people, this at a time when the blind are being encouraged to not use the paratransit system. If this continues the blind will have two choices, surrender their independence and have someone drive them everywhere, or take their life even more in their hands. I for one, think people should be able to safely walk the streets to get where they need to go each day on foot if they please. That means that the hybrid cars must be modified to make some kind of noise so that we will be able to identify them when we try to cross streets."
-- Sue Ellen Melo, Cleveland, Ohio

While the increasing prevalence of quiet vehicles may seriously affect the ability of blind and otherwise disabled people to travel safely, low-noise vehicles are also likely to affect the safety of sighted pedestrians and cyclists.

Sighted people also rely on sound at times to alert them to the presence of vehicles outside their line of vision. Hearing the approach of a car, they can glance in its direction to gauge its speed and location. It is no
accident that generations of schoolchildren have been taught to "stop, look, and listen" at every intersection. Both blind and sighted pedestrians make better decisions about crossing streets when they can hear vehicles in their environment.


Three basic approaches currently exist to solve this serious problem.

The first would involve the emission by vehicles of a silent radio transponder, infrared, Bluetooth, or other signal which would activate a receiver carried by anyone who needed the audio information. The second would involve a sound source, which instead of operating continuously, would rely upon the driver to activate it at crucial times. The third involves adding a sound source that would be audible whenever the vehicle is in motion or stopped at an intersection.
The first would force blind pedestrians to carry around yet another piece of technology. Such a device might be mounted on a cane handle or on the harness of a guide dog. However, no device in the foreseeable future is likely to give pedestrians as much information as they now receive audibly about vehicle position and traffic flow. In addition, many of us would not want to rely upon technology that could fail at a critical time should a battery run down or the device simply stop working.

The second would rely upon the judgment of the driver to activate the sound at the appropriate time, and this would also take responsibility for our safety away from us.

The following comes from an experienced Certified Orientation and Mobility Specialist:

"We cannot rely on drivers to be cautious about pedestrians who are unaware of their presence. Pedestrians and drivers alike are taught as children that pedestrians are responsible to "look and listen" for cars, and indeed research in the United States reveals that drivers do not reliably yield to pedestrians, even those with white canes {Geruschat and Hassan, 2005, Guth, Ashmead, Long, Wall & Ponchillia, :2005, Inman, Davis and Sauerburger, 2005, Sauerburger 2003}. For example, drivers who turn right into busy streets from a driveway or turn right on red often do not look to their right before moving forward because they are looking for a gap in traffic to their left; as a result, I know of a half dozen people who have been hit by vehicles as they crossed in front of the drivers from the drivers' right."
-- Dona Sauerburger, COMS®, Gambrills, Maryland

The third would involve the installation of a device that would emit a sound. For example, Hybrid vehicles could be manufactured so that the radiator fan switches on whenever the car is operating in electric mode, emitting a hum audible to pedestrians. Perhaps a device built into the axle could make a sound as the wheels rotate.

"Having vehicles produce an audible indication of their presence, designed to be inoffensive to the public, seems most workable. This engineering solution would most likely be an inexpensive minor modification to the existing design of the automobile. It could sound at lower speeds but disappear at faster speeds where car tires and air movement can easily be heard. Vehicles should emit a recognizable sound or class of sounds that can be localized; it is not necessary that this sound duplicate the engine noise we hear today. Such a modification should not require or allow operator intervention. A "minimum standard" for sound level should be established, regardless of the type of engine a vehicle uses." { National Federation of the Blind, 2006}

"While these hybrid cars are absolutely wonderful for the environment, I definitely have concerns about them as a blind pedestrian. These cars are very popular here in California. I truly believe that the manufacturer ought to think about placing a beeper or something on the car which would emit a noise so that we who are blind can hear that the car is close to us. Otherwise, we have no way of knowing that we're nearby such a car."
--Linda Gehres, Alameda, CA

It is not a difficult issue to determine when quiet cars should emit extra sounds. They should do so when stopped, when accelerating, when slowing down, and in fact whenever their gasoline engines are not operating. All vehicles which so outweigh pedestrians as to make any contest ridiculous should emit noise when they are being operated--no noise when in the driveway for the night or in the garage for the weekend, but when someone crawls behind the wheel, that vehicle should start making some level of sound.
-- Gary Wunder, Columbia Missouri


Developing solutions to this issue is becoming more and more critical every year, as more and more quiet cars appear on our roadways.

An urgent dialogue must take place, involving the auto industry, trade unions that represent auto workers, government regulatory bodies, and the disabled community, especially organizations "of" persons who are blind and partially sighted. Such questions as cost, effectiveness, and technology are all questions that need to be examined and resolved.

Additional research into various ways of adding a noise to a car could prove very useful. However, planning, funding, conducting, and analyzing research studies is a slow process at best. Time is of the essence. This work must take place before individuals are killed because they could not hear an oncoming quiet hybrid stalker.


Bartlett, Alan THE HYBRID CAR IS HERE TO STAY, Blind Citizens News (Australia), September 2004

Geruschat, Duane R. And Hassan, Shirin E. (2005) “Driver Behavior in
Yielding to Sighted and Blind Pedestrians at Roundabouts” Journal of Visual Impairment and Blindness, Volume 99, No. 5

Guth, D., Ashmead, D., Long, R., Wall R., & Ponchillia, P. (2005) Blind and Sighted Pedestrians’ Judgments of Gaps in Traffic at Roundabouts. Human Factors

Inman, V.W., Davis, G.W., and Sauerburger, D. (2005). “Roundabout Access for Visually Impaired Pedestrians: Evaluation of a Yielding Vehicle Alerting System for Double-Lane Roundabouts” 2005 Roundabout Conference Proceedings Transportation Research Board, Vail, Colorado

Kilpatrick, Kim, HYBRID CARS POSE NEW DANGERS, Canadian Blind Monitor, volume 21, Summer/Fall 2005

National Federation of the Blind, QUIET CARS AND PEDESTRIAN SAFETY: Problems and Perspectives," Report of a Conference at the National Federation of the Blind, November, 2006

Sauerburger, D. (2003) “Do Drivers Stop at Unsignalized Intersections for Pedestrians Who are Blind?” Proceedings, conference of Institute of Transportation Engineers, March 25, 2003, Ft. Lauderdale, FL

Stein, Debbie Kent, "Stop, Look and Listen," The Braille Monitor, June 2005

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