PBPhantom

My experience - almost a rear end collision!!

setup:
1. on adaptive Cruze... approaching a red light.
2. Car (1) in front changes lanes
3. Car (2) at red light

Action:
As the car 1 departs lane ...still a ways from the intersection, my car speeds up. It fails to "see" the stationary car2 at light. If I don't intervene and hit the brakes hard, I would be in a rear end collision.

snagitseven

The manual states that Presense front, a sub system of ACC, will not react to stationary objects unless they were previously detected as moving. When the followed car moved out of the ACC range area, the system would not recognize the stopped vehicle that was in front (nor a wall, fence, pole, etc.). This is normal behavior for ACC and a good example of why it should be treated as an aid and not a substitute for driver intervention.

Viper TT

Agreed! We had a Prius with ACC and we could easily switch over to standard cruise control if we chose. The Prius gave the driver the option on which style of CC to use.

q5q7

Thanks for sharing this experience. luckily i didn't experience this. good warning for other users.

q5q7

in what cases you think a standard cc is better than acc?

standard cc will only engage at higher than 30mph right?

when you approach a slow vehicle it will disengage itself instead of slowing the vehicle down.

snagitseven

Unlike ACC, "standard" CC is a "dumb" system that can only be disengaged manually by the driver, either by turning it off or hitting the brake pedal. It will happily plow right into a followed car if the driver doesn't brake.

q5q7

I see, so I don't get why two posters think standard CC is sometimes more useful.

snagitseven

I think it comes down to that some folks prefer complete manual control of the car and don't care for automated systems. There are some that decry automatic transmissions vs. manual stick shift for the same reason. While most folks embrace the new systems that generally improve safety, comfort and driveability, there will always be some that prefer the older ways of doing things as technology advances.

SamLV

If you have ACC, do you also get collision avoidance, which stops the car cold if you're about to hit something and moving under 20 mph? I ask because in my RL that feature saved me three collisions. And that feature can also go off falsely at speed, which in the RL meant a bell and vibration of the seat belt. Just curious about Audi on that score.

ACC I never did really like, because it would keep a distance, but always left so much room that in any traffic other cars just moved over, then it slowed more..... Or it would brake right when I'm about to go up to pass anyway... I never did get used to that.

superswiss

The distance setting on the stalk matters a lot for how smoothly it operates as well as whether you set it to Comfort, Auto or Dynamic in ADS. I personally have it set to Comfort when I use my Individual mode, which is most of the time. The optimum distance setting seems to be the middle setting. The actual distance is relative to your current speed if the car drives slow it closes in and if the car speeds up it increases the distance. In the middle setting it leaves enough actual distance to slow down by just letting off the throttle in most situations, unless the car ahead suddenly slows down rapidly. Generally, this also leaves a large enough gap for cars to cut in front of you w/o ACC going into panic mode. Nevertheless, I often push on the stalk to deactivate it if somebody pulls in front of me and then resume at which point it gradually adjusts the distance by letting the car in front pull away before accelerating again. The lower the distance setting the more it goes into panic mode, because you let it close in on the car in front too much and then it must apply the brakes to slow down. I don't have Stop & Go in my car, so I can't comment on how it behaves below 19 mph as mine disengages at that speed, however once I learned how it behaves and I figured out the optimum distance setting for various situations it works very well for me. I won't get a car w/o it anymore as it is a great feature on longer trips and in traffic.