Hybrid cars are too quiet: Risk Pedestrian Safety

In the true intrest of safety we need seperation, Planes in the air, seperated by 1000 of feet per direction

Cars on the roads seperated by a center barier, freight haulers con major highways only.

Bikes on seperate paths away from the road.

People on walkways seperated from both cars and bikes.

Differences in velocity and weight are what kills and hurts. All this roadway sharing is PC stupidity. Crossing at crosswalks only.

 

Although The Big Dig in Boston made national news for its mispending, its intentions were quite good: It buried a major roadway that passed through the city. In its place? Parks. One long strip of green running through the city.

Every urban street ought to be underground. A car is a deadly weapon you can buy without a gun license - deadly to a lot more than blind people. Streets are just ugly wastes of space, and once you reach a high population density you're going to get people crossing them at all hours.

Bury'em.

 

http://www.foxnews.com/story/0,2933,251998,00.html

 

There's already a thread on this here: http://priuschat.com/index.php?s=&show...st&p=389516

 

<div class='quotetop'>QUOTE(MegansPrius @ Feb 15 2007, 07:34 AM) [snapback]390833[/snapback]</div>

What's probably more accurate is that pedestrians aren't paying attention, and if they can't hear a car running, they assume there isn't one there at all.

I've had 2 near-misses in the last week with pedestrians running out in front of my car. The first was a girl who was running to catch a bus - I had looked right and left for pedestrians at the curb, but she was running from my right and in the time it took me to turn my head and glance left, she ran infront - I just managed to slam on my brakes before she got hit by my front-right bumper. I felt like crap, but in hindsight, it probably wasn't my fault.

The second time was driving into the parking lot at work - it's a slight down-angle and the engine had already shut-off as I neared the corner. A girl decided to cross just around the corner I was turning and didn't hear the car - I slowed down so she could continue to cross, but she gave me the dirty eye - although she was the one not paying attention.

Grr...

 

This happens a lot in the parking garage at school. People are walking to their car and will not even look before they cross over to their car. At first I thought is was because usually my car is running on the electric engine until I was in my friend’s truck and it happened to him twice and he drives a huge turbo diesel. I have even seen people wearing their ipod headphones and they will not even look. So I don’t think the prius being quiet has anything to do with it if people cant hear a diesel truck in a parking garage.

 

There is far more danger from the use of an Ipod than a Prius. Either one means you don't hear the vehicles. Darwinism at work.

 

Why would they start looking now? It might distract from what they are really intent on doing which is something else other than risking their lives in a auto roadway where they might get run over. The list is very long but rarely includes being carefull about traffic.

 

Oh heavens that we should have cars on streets anyway.

 

<div class='quotetop'>QUOTE(mikepaul @ Feb 14 2007, 01:48 PM) [snapback]390450[/snapback]</div>

What I really want for my Prius is the ability to reproduce what comes AFTER the MARTIAN1_sm sound: http://www.starships.com/Music/Streaming/MARTIAN3_sm.aif

(After all I drive in the irresponsible drivers, pedestrians & bicyclists capital)

 

Hi All,

I think MarkMN and Darelldd have the jist of the problem correct. Its not that Prius are all that quiet, they are not. Its that all the other ambient noise is so high. Tire noise is not descernable, because all cars make it. Even though the other cars are farther away than an approaching Prius, there are so many other cars, that the sound pressure with that harmonic pattern is as strong from the other cars, as the approacing Prius. Lets remember most engine noise is from the exhaust, and the exhaust noise is mostly shield from the forward direction by the bulk of the car. Tire noise is much louder than engine noise at safe urban traffic speeds.

Blind people are saying this is an unfair situation for them, but its not. I am sighted and hearing, and I have a similar situation each day walking between buildings at work with Aircraft overhead. The aircraft can easily drown out 18 wheel trucks in the industrial park that are coasting into a stop. As there is a curve in the road on this route, the 18 wheel truck can easily be outside the span of my vision, yet be 20 yards away moving 10 yards a second, and auditorily undetecable.

I have somewhat trained hearing due to various professional and amateur activities. Besides having had 2 blind acquintances over the years, and having become aware of the extreme auditory acuity of blind people. Which I have worked on emulating. I once detected noisey group of pre-teen girls on the side of an unlit road 75 yards away from the driving seat of a noisey car, which were totally invisible due the lighting and terrain. My brother in the passenger seat of the car was amazed at this, as he had not detected them at all.

What is unfare is that they are blind, and the solution to that is the seeing-eye dog, or to ask for help from a sighted person. The cane caried by blind people and other visual cues imediately communicates to most sighted people the situation, and they are willing to help.

Driving my Prius, I beep at any pedestrian not making eye contact , and within walking range of the path of my car, by the time my car would reach them at the speed I am going. Probably a good thing to do whether the pedestrian is blind, or not.

Here is a possible technical solution. Once I was driving along in the Prius in electric mode. As I approached a pedestrian walking a dog (a large german shepard), the dog immediately stopped and turned and looked. The dog probably heard ultrasonic noise from the hybrid inverter or motor being driven by ultrasonic inverter electrical pulses.

An ultrasonic downconverter could readily be made and it might reliably alert blind people to hybrids in the area. Downconverting would increase the detectability of the dopler shift as well.

For Bigger hybrids this is not a problem. A RX400H for example emits inverter/drive train noise at about 15 KHz, and is readily heard by pedestrians. This is based on personal experience of having a RX400H in electric mode approach me from behind, on the left side of the street, as I was walking on the edge of the road on the left side of the street.

 

http://www.youtube.com/v/Sol2MpIy5Rg

Sorry, couldn't figure out how to embed the video.
If a mod knows how, by all means, please.

 

Quiet powered vehicles in a city are nothing new. San Francisco has miles of public transit routes serviced by electric trackless trolleys, powered from overhead wires. Their electric motors are extremely quiet. Are there any other cities still running such trolleys?

If they aren't required to have noisemakers, why should autos?

 

With my A/C going and the noise of a couple of fans running, my Prius is just as noisy as any auto. Try it, get out in front and listen.

 

I plan to attend the hearing on "Quiet Cars" on Monday, June 23. But since I'll be in the area, I've made reservations for Saturday night in Norther VA and Sunday night near the MD line for dinner and "20 of my closest friends:"

http://priuschat.com/forums/local-c...590-mr-wilson-goes-washington.html#post635722

Please share the invite and if you're in the area, come on down and let's talk 'technical.':horn:

Bob Wilson

 

True, I noticed that now that it's heating up here in AZ. With the A/C on while it's hot, my Prius is actually louder than my Jeep (which has a mechanical fan).

 

It's a non-issue.

... Brad