[mgh]

Anti-lock braking system - Wikipedia, the free encyclopedia

para on regulation

ABS systems are required on all new passenger cars sold in the EU since 2007. In the USA, the NHTSA has repeatedly considered mandating anti-lock brakes on light vehicles, but has held off due to concerns over testing procedures and real-world crash data that failed to meet expectations.

earlier it is said

When drivers do encounter an emergency that causes them to brake hard, and thus encounter this pulsing for the first time, many are believed to reduce pedal pressure, and thus lengthen braking distances, contributing to a higher level of accidents than the superior emergency stopping capabilities of ABS would otherwise promise.

[speedsatya]

I see marks on the road surface starting from the side railings ! Which means these are the marks caused by the roof dragging on the road after the impact with the side railings and not the tires .

There are no skid marks before the railings ,which means he didnt brake at all and only swerved.

But why did he have to swerve .This looks like a straight stretch and even if there is a vehicle in front ,one can easily notice it from a distance at 140 kph .

ABS does cause vibrations on the brake pedal,but these vibrations arent so much that one can get scared and confused to lift from the brake pedal .

Also the distance to the toll booth is so much that the SUV would have slowed down by itself had the driver used engine braking .

I somehow dont buy this story ..this driver might be tailgating someone who must have slowed down or must have lost control at higher speeds!!

And yeah ,kudos to you on helping the injured occupants of the SUV

[Suess]

Originally Posted by shimshumara

is there some video or pictorial representation of how exactly ABS works?

here it is:

HowStuffWorks "The ABS System"

to read about it:

Anti-lock braking system - Wikipedia, the free encyclopedia

here is excellent video from Robest Bosch, the inventors of ABS:

Antilock Braking System ABS

and excellent resource on info about ABS/ESP:

Safe braking with the ABS

for more videos you can search youtube there are several videos on it.

how this helps to understand better.

[mayankk]

Additionally a skidding wheel causes resistance at the hub or deceleration, which is sensed by the ABS system, and it relieves just enough pressure on the brakes to allow minimal rotation.
No matter which way the wheel is turned, if it starts skidding, the car will go in only one direction - forward.
a better understanding of the pulsation on the pad can be seen by the staggered skid marks frantic braking on an ABS equipped car leaves.

[honeybee]

Keyur, hats off for what you did. I am sure people, if they had stopped at all, would have clicked snaps, discussed the accident and moved on. You not only helped the victims but also posted your thoughts here so the matter could be debated. Both the acts deserve an applause.

I think after all these posts, the only lesson we can learn is that we must invest time in learning the various driving features of our vehicles, specially when there is a lot of modern technology coming in and the drivers (salaried/contract) are not particularly well trained to utilize it. In this instance it seems a safety feature actually brought doom onto the vehicle because the driver wasn't equipped to handle it. Let's make sure we don't land up in this situation by training ourselves and our drivers in such important matters. If we learn to do that, I think the purpose behind your posting this thread will have been served.

[VW2010]

It just looks like the drive just slept, hit the railings too late to realise about braking and by that time the car was already tumbling.

I still cannot believe how the car tumbled. Thought the body roll was not high on captiva(Sarcastic tone).

Even if the abs caused vibrations, i feel the human brain would have been in a state to just ram the brakes and continue to ram the brakes and not take the feet off.

There is no way i can control hitting the brakes in many occassions while driving. From my personal experience the instinctive mind kicks over and just does what everyone would do. Try using whatever strength we have to hold on to the steering as well as hit the brakes. In this case either the driver was drunk or sleeping.

[Zed]

Originally Posted by speedsatya

There are no skid marks before the railings ,which means he didnt brake at all and only swerved.


ABS does cause vibrations on the brake pedal,but these vibrations arent so much that one can get scared and confused to lift from the brake pedal .

Originally Posted by VW2010

It just looks like the drive just slept, hit the railings too late to realise about braking and by that time the car was already tumbling.

Even if the abs caused vibrations, i feel the human brain would have been in a state to just ram the brakes and continue to ram the brakes and not take the feet off.
.

Gents, have to respectfully disagree with your comments not based on my perception but on evidence from newspaper reports \ first hand information.

1. The lack of skid marks is most likely indicative of the ABS doing what it was supposed to - i.e prevent the wheel from locking up and making it possible to steer while braking heavily which is impossible with a pair of locked wheels.

2. There are many recorded instances of drivers getting confused with the feedback from the brake pedal when ABS activates. For many of us it would be natural to just keep our foot planted on the brake pedal no matter what the feedback from the pedal is like or the lack of it, in the case of non-ABS vehicles. However that does not mean that some (many?) drivers will momentarily get confused when the brake pedal starts juddering & instinctively take their foot off the pedal + provide incorrect steering inputs on account of their confused state of mind.

One of lessons imparted during my drivers training in Germany was effective emergency braking. The instructor would take me to a street with minimal traffic in a non residential area, ask me to drive at around 40-50 kmph and bring the car to halt by standing on the brake. I mean literally standing on it. My first few attempts, which I thought were spot-on, did not impress him. His feedback was ' 100% pressure from the moment your foot touches the pedal, no pumping, no gradual increase in pressure - stand on it! '. Perhaps this was being suggested since ABS is pretty standard in most cars here. After about 3 - 4 attempts he gave his nod of approval. Although the road surface was excellent and it was a bright sunny day, the ABS did kick in towards the dying moments of each braking cycle. I would certainly comment that it wasn't a mild \ gentle vibration, it was quite a noticeable judder under the sole of my right foot.

In conclusion - my vote is with the author of the thread ( Great Job my friend, with the help you rendered and for posting this thread) that there needs to be increased awareness of ABS. Safety equipment such as belts, airbags and passive features such as crumple zones work without any intervention and there is no 'feedback' to the driver which is why we need to look at ABS with different lenses, from a driver training perspective.

Perhaps OEMs, in conjucction with their distribution network, can ensure that potential customers \ customers get to experience ABS braking first-hand during Test Drives or delivery. Trusting our driving schools \ RTOs with this job would be expecting too much, I suppose.

[devansn]

Keyur, you deserve a pat on your back for what you did - quite uncommon.

About the seat belt / air bag - when to deploy the airbag upon collision (when the seat belt is buckled / not) is probably purely implementation specific, but the one thing I am convinced is that without wearing seat belts, air bags are useless. Seat belts are THE PRIMARY safety equipment. I don't know why people get ashamed of wearing seat belts - their ego get hurt when someone asks them to buckle up! So many instances I have spoiled personal relations with many by insisting to buckle up. :-)

I used to believe that ABS gets activated only on sudden deceleration, but I stand corrected now. I have felt some vibrations on the brake pedal even at speeds close to 20-30 kmph, on roads with sand / small pebbles - I showed it to the service center a couple of times, but they could not find anything wrong. Now I know why so.

Originally Posted by cranky

What was the speed limit on the road, and was he driving within that limit?

Driver error, not ABS.

With due respect to the law / rules, I beg to slightly differ here. I think rules are for the weak - those who cannot judge their / their vehicle's limitations. I mean, even 100 kmph is not a safe speed for many vehicles / drivers in particular driving conditions - its all relative. Ultimately it is for you to decide what is the speed you can take on your vehicle in different conditions. I think the driver's ethics is what matters - to be responsible and make sure his and other's safety. If even hacking can be done ethically, why not speeding?! :-)

[mayankk]

Originally Posted by devansn

With due respect to the law / rules, I beg to slightly differ here. I think rules are for the weak - those who cannot judge their / their vehicle's limitations. I mean, even 100 kmph is not a safe speed for many vehicles / drivers in particular driving conditions - its all relative. Ultimately it is for you to decide what is the speed you can take on your vehicle in different conditions. I think the driver's ethics is what matters - to be responsible and make sure his and other's safety. If even hacking can be done ethically, why not speeding?! :-)

I do hope you understand that the road is a shared space.
If everyone starts driving as per his/her own limitations, there wont be just one overturned captiva in the pictures.
If adjudged speed limit on a road is 80Kmph, it is not to limit one's enjoyment.
you could take a corner at 130 kmph, ok.
what happens when you come to the exit of the corner, and there are 4 vehicles abreast who think that their vehicles/abilities end at 60 kmph?

[honeybee]

Originally Posted by VW2010

It just looks like the drive just slept, hit the railings too late to realise about braking and by that time the car was already tumbling.
... In this case either the driver was drunk or sleeping.

I think the OP mentioned the owner had conversed with the driver as he got ready to pay the toll. We can safely conclude the driver was neither sleeping nor drunk.

Originally Posted by devansn

I think rules are for the weak - those who cannot judge their / their vehicle's limitations. ... If even hacking can be done ethically, why not speeding?! :-)

Please take part in motorsports, but not on the public roads. I am not sure I understand your intention in posting this message, but I for one think it's highly inappropriate to even think this way.

Originally Posted by mayankk

I do hope you understand that the road is a shared space ... what happens when you come to the exit of the corner, and there are 4 vehicles abreast who think that their vehicles/abilities end at 60 kmph?

Very well put. You absolutely MUST respect other road users, though they may be driving vehicles which cannot match your own for speed.

[speedsatya]

Originally Posted by Zed

Gents, have to respectfully disagree with your comments not based on my perception but on evidence from newspaper reports \ first hand information.

1. The lack of skid marks is most likely indicative of the ABS doing what it was supposed to - i.e prevent the wheel from locking up and making it possible to steer while braking heavily which is impossible with a pair of locked wheels.

2. There are many recorded instances of drivers getting confused with the feedback from the brake pedal when ABS activates. .

I agree to some extent with whatever you have said .

Standing on brakes is possible in Germany as almost every car would have ABS ,but here in India ,its very few vehicles that have the ABS.Standing on the brakes in a non-ABS equipped car could be equally dangerous ! As in India ,ABS,EBD ,airbags... are marketed as expensive add ons than life saving compulsory requirements on every vehicle

And yeah ,I do understand that the vibrations of the brake pedal can be scary for a first time driver ,but I strongly believe that most of us would stand on the brakes no matter what feedback it gives in terms of vibrations .

This thread could be renamed as "Understanding ABS "

But something still tells me that here it was a case of lost control than understanding ABS. Any obstacle at any speeds can be identified on this straight stretch ,unless the driver was trying to avoid an ant !

[kiku007]

First of all kudos to the thread starter! How many of us would have done that?! Great job.

Originally Posted by speedsatya

Standing on brakes is possible in Germany as almost every car would have ABS ,but here in India ,its very few vehicles that have the ABS.Standing on the brakes in a non-ABS equipped car could be equally dangerous ! As in India ,ABS,EBD ,airbags... are marketed as expensive add ons than life saving compulsory requirements on every vehicle

Standing on the brakes even in a ABS, EBD, TC etc. equipped car here in India without having a look at that rear mirror for a fraction of a second is also risky. There are so many morons following so closely behind and if it's a Taxi, forget about ABS I don't even know if it has proper brakes!

[Vtecguy7166]

Even in my car I have experienced ABS kicking a lot of times. This is definitely a driver error. I have seen a lot of people doing sudden braking instead of gradual slow down.
They drive as if driving on a race track.

[good.car-ma]

Originally Posted by devansn

So many instances I have spoiled personal relations with many by insisting to buckle up. :-)

With due respect to the law / rules, I beg to slightly differ here. I think rules are for the weak - those who cannot judge their / their vehicle's limitations. I mean, even 100 kmph is not a safe speed for many vehicles / drivers in particular driving conditions - its all relative. Ultimately it is for you to decide what is the speed you can take on your vehicle in different conditions. I think the driver's ethics is what matters - to be responsible and make sure his and other's safety. If even hacking can be done ethically, why not speeding?! :-)

I salute your stand on seatbelts as it is right but your subsequent statement appalls me! It is ridiculous to compromise road safety for personal pleasure. Remember that others are dependent on your driving and vice versa.

It could very well be that your wife/child/mother is driving at a low speed and a person who thinks like you is driving at a high speed and the end result is an accident. Would you still say that its all in the game since rules are for "the weak" who in this case, turned out to be your loved ones???

Also, there are rules for common safety. You may very well have the 'ability' to drive after a couple of drinks or to drive while chatting on a mobile. You may be expert enough to do it but we DO NOT do it because there are rules in place so that others are safe as well. Driving on public roads is not a question of superior ability or strength/weakness, it is about SAFETY!

I really hope you can understand my point and respect road rules just as much as you respect the use of seatbelts.

Originally Posted by mayankk

I do hope you understand that the road is a shared space.
If everyone starts driving as per his/her own limitations, there wont be just one overturned captiva in the pictures.
If adjudged speed limit on a road is 80Kmph, it is not to limit one's enjoyment.
you could take a corner at 130 kmph, ok.
what happens when you come to the exit of the corner, and there are 4 vehicles abreast who think that their vehicles/abilities end at 60 kmph?

Extremely well said!

Originally Posted by honeybee

Please take part in motorsports, but not on the public roads. I am not sure I understand your intention in posting this message, but I for one think it's highly inappropriate to even think this way.

Well said! Public roads are not for showing off. They are for getting from point A to point B. The track is where you should showcase your ability.

[devansn]

Originally Posted by honeybee

Please take part in motorsports, but not on the public roads. I am not sure I understand your intention in posting this message, but I for one think it's highly inappropriate to even think this way.

Very well put. You absolutely MUST respect other road users, though they may be driving vehicles which cannot match your own for speed.

Originally Posted by mayankk

I do hope you understand that the road is a shared space.
If everyone starts driving as per his/her own limitations, there wont be just one overturned captiva in the pictures.
If adjudged speed limit on a road is 80Kmph, it is not to limit one's enjoyment.
you could take a corner at 130 kmph, ok.
what happens when you come to the exit of the corner, and there are 4 vehicles abreast who think that their vehicles/abilities end at 60 kmph?

First of all, really sorry if I could not put it right and sounded foolish and rude on my previous post.

I did not mean that one should not obey the rules and regulations and should take speeds that the vehicle can achieve. Ethical driving includes making sure that the driver, his co-passengers and the other vehicles / people / public property etc. are not harmed. The speed limit is just a very approximate indication of the max speed one can take to avoid any accidents - especially because the safety features on vehicles here in India vary too much - we have TATA Nano as well as expensive BMWs, both legal to be driven on expressways. Even the posted speed limits in certain situations are not safe. Although there are no minimum speed limit on any highway, I think being very slow on a fast moving express way is equally dangerous to all. For instance, learning driving on an expressway (provided the learner has a valid learners license and the co-driver has a valid drivers license and all the vehicle papers are correct) may not be illegal, but is certainly unethical. I hope I am clear now. Sorry for going off topic, though I think if drivers don't inculcate good ethical driving manners, safety features like ABS or air bags have their limitations. Safety features are meant for the worst, not to be used everyday.