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Old 5th May 2013, 09:52   #436
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Default re: The ABS discussion thread

As stated above pump braking will only increase the braking distance.

Back in my home country I used to take regular courses on what was known as advance car control. In essence racing, but somebody thought this sounded better.

Anyway, part of every course was always braking. Endless braking. The braking technique I was taught on non-ABS equipped cars was as follows:
- Slam on the brakes as hard as you get.
- When the wheels lock come off the brakes a tad so the wheels keep rolling

Everybody can learn this trick. They had a couple of VW Golfs fitted out with a little switch to switch on or off the ABS system at will. For most participant they could outbrake the ABS system within half an hour of training.

The biggest thing is, that it's easy to pick up a trick like this for most of us on a training circuit, even become familiar with it. Using it the next day, or the next month or half a year later in a real life emergency stop is a different thing all together. That's why ABS is so valuable. You just slam on the brakes and the electronics do the rest. Yes, if you are an outstanding driver and practice a manual braking technique you could possible outbreak the ABS system. But for most of us, that's simply not the case.

There has been one thing with ABS though, especially on the earlier systems. In order for it to kick in, you had to press hard, real hard. Not everybody could, especially women found it difficult! I know my wife did. Also, sometimes the pulsing of the brake pedal would inadvertently let some persons to release the brake. Again, with modern systems this has much improved.

Apart from the cost and the safety factor there is something to be said for having all cars equipped with ABS. If the car behind you doesn't keep its distance and doesn't have ABS and you do, in case of you hitting the brakes in an emergency, guess who's going to end up in your rear?

I'm from Europe and most new cars sold these days have ABS fitted as standard. Even one of the cheapest new cars on the market, the Suziki Alto comes standard equipped with not only ABS, but also EBD (electronic brake distribution) and BAS (brake assist system)

http://goedkoopsteauto.eu/suzuki-alto-2012.html (Dutch link to the cheapest cars in the Netherlands)

Jeroen
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Old 5th May 2013, 20:37   #437
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Default re: The ABS discussion thread

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... there may be over 10 airbags ready to expolde inside your car in the case of an impact. If your crash is high speed and long-lasting, these airbag detonations may well impair the driver's ability to control the vehicle. ...
In the scenario you are describing, no amount of control of the vehicle is going to do any good - too late. The Airbags are for limiting the seriousness of the injuries to the occupants.
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Old 5th May 2013, 23:31   #438
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In the scenario you are describing, no amount of control of the vehicle is going to do any good - too late.
Just not true. Once airbags have gone off, for a short while a vehicle's occupants may be stunned, visibility will be nil and there is a high chance of injury from the airbag itself. Spectacle wearers are particularly prone to injury especially if the lenses are glass.

In a multiple-impact accident the detonation of airbags renders the driver incapable of being aware of what is happening. There are plenty of circumstances where steering and braking still work, even though the driver probably isn't in full control. Crude but potentially vital adjustments may be made to the vehicle's progress before it comes to a halt which could prevent further serious damage.

Equally, the detonation and explosion of airbags in a single-impact accident means the driver and passengers may be stunned for a little while and will not be as aware of what is happening outside the vehicle. They may be unknowingly in the path of oncoming vehicles which cannot avoid the crashed car.

Airbags are a worthwhile safety feature but it is well-recognised they are not ideal in every crash - the multiple impact accident being one of them. Be aware that short people are particularly in danger of serious injury from airbag deployment and children should never be seated behind front airbags. Many have been killed by the airbag itself.
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Old 5th May 2013, 23:36   #439
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Default re: The ABS discussion thread

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Originally Posted by FlatOut View Post

In a multiple-impact accident the detonation of airbags renders the driver incapable of being aware of what is happening. There are plenty of circumstances where steering and braking still work, even though the driver probably isn't in full control. Crude but potentially vital adjustments may be made to the vehicle's progress before it comes to a halt which could prevent further serious damage.
There is something called acceptable risk.
For example, lets take the seat belt.
We all know seat belts increase safety. But then, it is entirely possible that there was an accident where the driver could not remove seatbelt, and therefore drowned as the car fell in a lake.
So seatbelts killed.
Now if a seatbelt kills one and saves 100, its acceptable risk.

Similarly, there have been cases where airbags caused burn injuries which would not have been there otherwise. But then.. acceptable risk.

Now coming to your car control scenario. I am very interested in knowing what type of collision would cause the airbag to explode, yet not render the car uncontrollable.
Do you have any links or news items or studies? You made a very interesting comment which ignites my curiosity, and I would like to read up some more
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Old 5th May 2013, 23:47   #440
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Default re: The ABS discussion thread

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Originally Posted by FlatOut View Post
... There are plenty of circumstances where steering and braking still work, even though the driver probably isn't in full control. Crude but potentially vital adjustments may be made to the vehicle's progress before it comes to a halt which could prevent further serious damage. ...
Err... do you realize the Airbags would have been activated in a situation that impedes the vehicles movement? Crash? Rapid deceleration till you can't go any further? What "vital adjustments" would / can be made under those circumstances? The time between Airbag firing and complete stop is usually 0.5 seconds.

The only exception is side impact, which don't activate the front airbags - the driver is theoretically still in control in that situation.
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Old 6th May 2013, 00:03   #441
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Default re: The ABS discussion thread

"Rapid deceleration till you can't go any further" is what is called a single impact crash. You hit something, you come to a rapid halt. Airbags are most likely to work best in this sort of crash.

A multiple impact accident is what is usually called 'a long crash' and would usually occur on a road with two carriageways each carrying traffic which is moving in just one direction (we call it Motorway in Britain, not sure about your name).

The first impact is one which doesn't stop the vehicle, but deflects it. There is often relatively little deceleration caused by the impacts. At high speed there may be several impacts before the vehicle comes to rest, I have seen such accidents take place over almost a kilometre when the road is slippery or wet.

Crash barriers are the usual obstacle, having either lost control of the vehicle through a bend, having been hit/having hit another vehicle or being forced to swerve to avoid something.
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Old 6th May 2013, 04:03   #442
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Default re: The ABS discussion thread

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"Rapid deceleration till you can't go any further" is what is called a single impact crash. You hit something...
Yes, You hit something, around about the same time as your car hits something. If you hit it hard enough to inflate the bags, you are probably not concious to control the car if it goes on moving. And yes, airbags in the face/chest hurt --- but not as much as the steering wheel. A friend of mine found this out recently, but I think he was happier with what the airbags did to him than what the car might have.

There is always some valid exception. A high-speed rear ending that pushes the car forward, perhaps engine running, with driver's feet jerked off clutch and brake? Just an idea, valid or not.

The world is not exactly free of silly ideas, some of them lethal, but airbags and seatbelts seem to be pretty sound by the vast majority of the experience.

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The first impact is one which doesn't stop the vehicle, but deflects it. There is often relatively little deceleration caused by the impacts. At high speed there may be several impacts before the vehicle comes to rest, I have seen such accidents take place over almost a kilometre when the road is slippery or wet.
In this kind of instance, I wonder what happens to the driver on the next, or subsequent impacts, and no, I don't fancy it. The airbag is already deflating as the occupant hits it, so only one-time protection is there.

Actually, perhaps that is a pertinent point: for better or for worse it doesn't stay inflated.

Hmmm.... this is the ABS thread <Blush>
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Old 6th May 2013, 05:30   #443
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Default re: The ABS discussion thread

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Originally Posted by Thad E Ginathom View Post
The world is not exactly free of silly ideas, some of them lethal, but airbags and seatbelts seem to be pretty sound by the vast majority of the experience.

In this kind of instance, I wonder what happens to the driver on the next, or subsequent impacts, and no, I don't fancy it. The airbag is already deflating as the occupant hits it, so only one-time protection is there.

Actually, perhaps that is a pertinent point: for better or for worse it doesn't stay inflated.

Hmmm.... this is the ABS thread <Blush>

I agree on all counts! In order of most-beneficial safety, I would say seatbelts, ABS then airbags. But I can imagine certain accidents where the reverse may be true. Indeed I know of someone who was thrown through the windscreen in a crash, then the car exploded. Had he been restrained he would have perished.

My own concern with airbags is that they make it less likely that you see what is happening outside your car, either when you are still moving (and could take avoiding action) or when stopped and something is approaching you and going to hit you. Plenty of keen motorists in Europe and America actually remove them because of this. Airbags were originally intended to save the lives of those not wearing seatbelts. They have also maimed and killed a lot of smaller people with the violence of their deployment.

Just to prevent this thread from moving completely OT, the last thing you want if driving in snow which is deeper than 3-4 inches is ABS. Audis used to have a disabling switch for just this reason.
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Old 6th May 2013, 05:54   #444
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Originally Posted by tsk1979 View Post
There is something called acceptable risk.

Now coming to your car control scenario. I am very interested in knowing what type of collision would cause the airbag to explode, yet not render the car uncontrollable.
Do you have any links or news items or studies? You made a very interesting comment which ignites my curiosity, and I would like to read up some more
I think I have explained in my other posts - in high speed motorway crashes, there are many 'long crashes' where the first impact is significant enough to set off the airbags but not to slow the vehicle significantly. Such a crash will begin with loss of control at speed from swerving to avoid deer on the road, debris, hitting black ice, being touched by another vehicle etc.

My point is that the explosion of airbags will most likely render the vehicle uncontrollable through the shock/stunning effect to the driver as well as a possible broken windscreen from the deployment of the passenger. In a 'long crash' if no airbags were deployed at the first impact, there is much more possibility of a driver retaining some control as the crash continues.

These accidents happen most in continental Europe where motorways are quiet and speeds very high - in excess of 200kph. Crash barriers usually retain the crash within the road. I have seen such accidents involving just the one vehicle which have taken place over the best part of a kilometre.

However there are accidents on conventional roads at high speeds where if the first impact sets off the airbags, it means the driver is reduced to having no control and simply waits for the vehicle to have other impacts before coming to a halt. If airbags do not deploy, there are situations where this is very definitely a good thing in the sense a driver can still have some control of the vehicle as it slows.

I am not some anti-airbag nutter, by the way - I simply like to point out they are not a universal good. Many children have been killed by them, lots of small adults and those who wear spectacles have been permanently injured by them. But of course the number of lives saved is much greater.
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Old 6th May 2013, 09:47   #445
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Default re: The ABS discussion thread

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I think I have explained in my other posts - in high speed motorway crashes,........
I read what you said. I would like some links to studies about the same. Or is this your own independent study about such cases? Do you have some data about such crashes which you came across while doing the study?
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Old 6th May 2013, 12:06   #446
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Plenty of keen motorists in Europe and America actually remove them because of this. Airbags were originally intended to save the lives of those not wearing seatbelts. They have also maimed and killed a lot of smaller people with the violence deploof their yment.
.
I've lived most of my life in Europe and several years in the States. I'm active on at least half a dozen car forums around the world including this one. I've yet to come across somebody that I know, or have heard from, that has disabled or removed their airbags. That is in Europe or the States.

As far as I'm aware just about all European/US cars had seatbelts and it was compulsory in most countries to wear them long before airbags were introduced.

Yes, there is some evidence that smaller people (or exceptional large) people do not benefit from Airbags. But to say they've maimed and killed a lot seems a little on the erronous side perhaps?

I know most cars these days are equipped with an "airbag switch off" option. Mostly used for when you have small children sitting in the front seat in a special baby/toddler seat.

Jeroen
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Old 6th May 2013, 12:15   #447
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... we call it Motorway in Britain, not sure about your name). ...
A 'Highway', in most cases, or an 'Express-way' (depends on what and how much political mileage is associated with either ). We have very few of those that are affected by icy conditions - water planing in wet weather is the closest one gets to.

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... The first impact is one which doesn't stop the vehicle, but deflects it. There is often relatively little deceleration caused by the impacts. ...
Not sure of the point you are trying to make here, in connection with Airbags:
* If there is a significant impact on the sides, the side (curtain) airbags will deploy
* Front airbags won't, unless the impact is frontal or diagonal frontal, i.e. roughly at the front corners. If diagonal, both front and side ones will deploy
* In none of these non-frontal-impact cases is there any cause for the driver to lose control - other than panic (side airbags don't obscure view)
* The vehicle could be deflected severely enough to cause a spin, without the airbags deploying - light side impact on icy/wet road, diagonal impact from rear under all circumstances etc.
* @Thad's Use Case of rear impact might cause the feet to rise off the pedals would cause loss of control for a short while. Hopefully driver, unless DUI or suffering severe whiplash that debilitates enough to lose control, would regain control

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Originally Posted by Thad E Ginathom View Post
... The world is not exactly free of silly ideas, ...
In a Failure Mode Effect Analysis exercise (commonly used in automotive & automotive systems design), all such ideas / cases are valid. Only the answers to some turn out to be 'silly'!
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Old 6th May 2013, 13:57   #448
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That "6K" ultimately adds 24K at least to the price of the car.
+1. Also, the ABS in Mercedes and Maruti (just for comparison), are technologically different right? In the sense that, one might work much better than the other and the cost will be on the higher side. In any case, 6k is too small a figure. Also, to sell ABS equipped vehicles, how many in the dealerships can explain this concept correctly?


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In India, one can get a driving license even if one hasn't *ever* driven a vehicle.
Sure, most of the junta buys a car without even a test drive, just going by word of mouth, then learn driving and at the same time get license in two weeks and then build confidence in their own cars.

The day we impose strict driving test for License in India,*the auto economy will plunder in to darkness*, but, the roads will be free for the *real* petrol heads.

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Old 6th May 2013, 14:56   #449
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... Also, the ABS in Mercedes and Maruti (just for comparison), are technologically different right? ... how many in the dealerships can explain this concept correctly? ...
Not really. There may be / are fine differences, but essentially they are the same. The major difference in cost comes only when other functionality is tagged on, like EBD or ASR.

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... then learn driving and at the same time get license in two weeks and then build confidence in their own cars. ...
No, no, almost every one in family and friends advise one to get a beat up 2nd hand car first - so that if you bang something the cost is less. Drivers coming out of this school of thought are generally much more confident on the road. Those who learn and then drive their own new cars immediately are the ones you are wishing were not there on the road! They are usually mortified of getting even a scratch, and are over-cautious.
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Old 6th May 2013, 16:37   #450
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I've lived most of my life in Europe and several years in the States. I'm active on at least half a dozen car forums around the world including this one. I've yet to come across somebody that I know, or have heard from, that has disabled or removed their airbags. That is in Europe or the States.

Yes, there is some evidence that smaller people (or exceptional large) people do not benefit from Airbags. But to say they've maimed and killed a lot seems a little on the erronous side perhaps?

I know most cars these days are equipped with an "airbag switch off" option. Mostly used for when you have small children sitting in the front seat in a special baby/toddler seat.

Jeroen
I have discussed this 'grey area' of airbag safety within this forum which I consider to be used by enthusiasts who are well-above average intelligence and who are better informed than most motorists. I recognise that in a country where airbags and abs are not mandatory fitments to new cars and where deaths on the roads are so relatively high, it is controversial to mention anything which isn't good about such safety items. I am not suggesting they are unsafe or not a good thing, rather that there are certain situations in which if you are in a car in which airbags have deployed, get over the initial shock as fast as possible and concentrate on what is going on outside.

I know of a couple of people who have disconnected their steering wheel airbags - they're both highly skilled and experienced drivers. But it's not something I suppose you broadcast. I leave my airbags in place, given that on balance they are a huge safety feature. It's just that like anything else in life, they are not perfect and in certain, rare-for-most-people circumstamces you may be better off without their deployment. I introduced this side of the airbag debate simply for completeness of discussion, not to try to undermine their important role in saving lives. The industry prefers them to other safety features (such as Audi's Procon Ten, which the insurance industry detested) because they are profit-high and easy, if expensive, to replace after an accident.

It is recognised that more children have been killed by airbags than saved by them, http://www.ajnr.org/content/19/9/1599.full.pdf but the numbers have dropped quickly as people have been educated to the risks, and switch off the airbags where children and babies are sitting.
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