Pre Sense almost caused an accident
03-18-2017, 08:02 AM
#11
AudiWorld Super User
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 ...
All of the other cars in my vicinity were several car-lengths away from me, so I don't know what triggered the warning.
Regarding other posts about who's liable in a rear-end crash, when I was a teenager driving my first car, a VW Beetle (doing about 30 mph on a local street), I was about a car-length or so behind the car ahead of me when the car in front of him stopped short, without signaling, to turn into a driveway. The car in front of me was able to stop, but I slid into him thanks to a homeowner who was tossing snow from his sidewalk into the middle of the street. I slid on the snow and rear-ended the car in front of me.
Who is at fault? The first car that abruptly slowed without signaling to make the turn, the guy in front of me who stopped short, me, who hit the guy in front of me, or the homeowner who was shoveling his snow into the street?
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03-18-2017, 08:13 AM
#12
AudiWorld Senior Member
Pre sense can be turned off in the MMI. Often my parking sensors have been going off while at stop lights. It's quite annoying. Cars around me are at a safe distance.
03-18-2017, 09:53 AM
#13
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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.
03-18-2017, 01:49 PM
#14
AudiWorld Senior Member
Pre sense in Premium and Premium Plus is pure camera based. It has it's advantages and shortages. My Honda has similar safety feature with both camera and microwave radar as sensors (similar to what's in Prestige trim). Construction sit's metal plates will bounce the radar signal sporadically triggering collision mitigation system. I have been driving the Honda (with Lane Keep Assist, Blind Spot Monitor, Adaptive Cruise Control and Collision Mitigation etc.) for almost two years now and have been familiar with all the situations thus learnt how to minimize the false alarm. Despite this or that minor issues, I still prefer advanced safety features in modern cars. It saved me once or twice from rear ending other people and make the night driving an ease.
03-19-2017, 06:51 PM
#15
AudiWorld Member
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, 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.
03-19-2017, 06:55 PM
#16
AudiWorld Member
03-19-2017, 07:33 PM
#17
AudiWorld Super User
Funny as it may sound, the only time my parking sensors went crazy was when I was following my X3. Whenever we stopped at the lights, the front sensors in my car would go off asking me to check the surrounding. I thought my sensors were acting up but I realised that when I was behind other cars (different lights but say there was a car between my X3 and A4), the sensors were fine.
That same day, I checked audiworld and found out that someone else had the same issue when they followed BMW SUVs!!! It was the first time my car was following a BMW SUV and it happened every single time we pulled up to the lights with my X3 in front. There was enough gap for maybe 3 or 4 people to stand one in front of the other.
I haven't been able to check it out since I've never been in a situation where there was a BMW SUV (or car) in front of me before or after that.
03-20-2017, 08:28 AM
#18
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Was the bike LOUD? I had the triangle and warning beep when a very loud bike went by me. I shrugged it off as vibrating the sensors. Never thought it would throw the brakes on. Theory, the SPL of bike noise vibrates the little diaphragms around the car causing a false radar bounce back?
03-20-2017, 09:40 AM
#20
AudiWorld Member
Right. It's really hard to prove fault.