AlainW

Hi all today I got the fright of my life when driving back from work. I was going 50mph on the expressway when suddenly a motorbike sped past to my left. The bike was at least 3feet away at any given time. However I got the shock of my life when my A4 suddenly applied the brakes while I had the foot resting on the accelerator. It was so sudden and jerky, on the spot I thought that another car had rammed into mine. Within a fraction of a second I was down from 50 to 30mph. The car didn’t come to a full stop. Luckily the car behind me was not tailgating, because I do not think that any human being would have fast enough reflexes to brake as fast. I saw a big red triangle appear on the dash for a few seconds, I think it said Pre Sense with a ‘!’ but I was too shaken up to really remember. Has this ever happened to anyone else? If I were rear-ended in this case whose fault would it have been? During my 6months of ownership this is the first time the car has braked on its own so violently, though I have seen the triangle appear a few times before with cyclists on the road.

salvadorsantana

Awww Pre Sense sometimes don't use common sense, this is when you get to try it out, in the real world, not on paper where it says what it would do or what it would not do. If you get rear ended it is the other person fault...unless you tell the cops the whole Pre Sense BS and probably you end up with the ticket lol.

I HATE Pre Sense especially when backing up into tiny spaces were I'm fully aware of the space etc and then the car decides to apply the brakes violently f*cking Pre Sense is all I can think at the moment .

Pre Sense is like that person that is scared to ride on the passengers side and you see them sometimes being nervous and pressing their feet on the floor like if there was a hidden brake pedal hahaha...that's Pre Sense.

Transporter208

The guy behind you would be considered at-fault most likely. Not maintaining a safe distance. This scenario you have describe is very disconcerting. It sounds like you could have been wrecked by this if that guy behind you wasn't paying close attention. Pre-sense technology is very popular right now on many brands and I wonder also if others have experienced a similar situation. Is there a way to turn it off on your A4 if you continue to have this issue?

ThePav

Never had that happen to me when a motorbike has passed me.

But I've had it happen to me when I was in the left lane going 80km/h (Australia) and there were cars in a right turning lane crawling along at about 10km/h, All of a sudden when I got near them the triangle and beep came up and it slammed on the brakes till I was almost at a stop.

Since that day I've tried to keep at least 1 meter from any slow moving car on my right and even then it can still pop up with the triangle and beep.

bob m

I "suppose" you are correct about the guy behind you being "at fault" and I am a firm believer that more than anything else, keeping a safe distance is your best defense against an accident, but as you mentioned, it's a good thing the guy in back was paying close attention. Going from 50mph to 30mph in an instant is very short notice and all the more worrisome and unexpected because that biker was on your side, not in front of you - where you would automatically be ready to apply the brakes.

But I will speculate about this situation - and we all know it happens. Suppose that you are driving along and you feel someone is tailgating you - or just driving too closely behind. Soooooooo, you want to "teach him a lesson" and you apply the brakes suddenly. Bang, you get rear ended. I am wondering if you are also at least partially liable for causing an accident? Yes, I know you can claim you thought you saw a deer jump in front of your car or something, but all things being equal, I'm guessing you'd be partly liable. To a certain extent, realizing that intent was not an issue, couldn't the other driver's insurance company make the claim that there is a shared liability for such an accident?

PeteDin206

My understanding is if you his someone from behind, you are almost always at fault. The only case would be if someone pulled out in front of you without providing enough room but that would be difficult to prove without a dash cam.

KevinB656

The following driver will be at fault whether the driver does the braking or the car does the braking. It is a following driver's obligation to keep a safe distance.

Bob M, there is a legal doctrine called last clear chance that provides that someone who might otherwise not be in fault could be in fault if it can be shown that such driver had the last clear chance to avoid the accident. In your example, the following driver might successfully argue that the braking driver had the last clear chance to avoid the accident (by not slamming on the brakes for no good reason) and therefore transfer the liability to the braking driver. Of course, as you say, it's very unlikely that the braking driver would admit to slamming on the brakes for no good reason.

Regarding pre-sense, I have had it engage a couple of times where it shouldn't have really had a reason. There was nothing that came close to causing an accident, though. I like having the pre-sense keeping an eye on things and can put up with a couple of false positives.

bob m

Makes sense. Thank you counselor. I like having pre-sense at the ready, but I still have to say, the OP's scenario scares me.

minmet

My pure speculation, any chance the bike is not running in a strict straight line right at the time. Bikers often swirl no mater slow or higher speed. If so, and happnedly the biker veer to slight right direction at that moment, the Pre Sense will view that as the bike is coming in front of you and too close thus applied the brake. I wouldn't see this as the Pre Sense malfunction, rather machine's (software) over judge in real world situation.

bob m

Could and probably is the case, but scary outcome nonetheless.