fnarq

I commute daily in the larger NY Metro area. I use a mix of 65mph interstate/freeways, secondary roads, NYC streets, country roads etc. I live in exurban farmland, and am in NYC at least twice a week usually. I have plenty of opportunity to use the A4's driver assist features, and wanted to share some of my feedback, and see what others think as well. My experience in my Audi will be mostly compared to my wife 2015 Subaru Outback. In general, I expect these systems to work mostly flawlessly, so I'll focus on things that I think could be improved.

1. Adaptive Cruise Control - Use it all the time. One thing I notice is that when the ACC is active, it seems late frequently in detecting when traffic is slowing down in front of me, and the car makes late stops, which is disconcerting to me and the driver behind me. It doesn't feel like the system recognizes brake lights on cars in front of me. Another thing I noticed with my car, is that when the ACC is toggling between accelerating/coasting/braking, I hear clicks emanating from the steering column/instrument cluster area. Does anyone else hear this? It's very repeatable, and I'm not sure if that's normal or not.
2. Traffic Jam Assist - for me, incredible. I'm in heavy traffic frequently for long periods of time and the stop-and-go can be murderous on a middle-aged guy's knees. This takes so much physical and mental stress out of my commute, I will never buy another car without it. I wish the "ACC automatic go" would stay active longer than three seconds though; I would like more like 10 seconds I think.
3. Active Lane Assist - I find that the system often struggles to see the lane markings on the secondary roads around me. Could be the salty roads, poorly-maintained markings, and not the fault of the car per se. However, since you're never sure when it will lose the lane markings, it's hard to rely on it. Also, I find that the system seems to make a decision on whether it wants to "snap" to the left or right lane markings. I find that when it snaps to the yellow line in the middle of a two-lane road it's way to close to the wrong side of the road... makes me and the drivers in oncoming traffic uncomfortable, you can tell because they all hug the side of the ride as they approach me. I have tried changing the setting for this between late vs. early, and am still trying to decide if either setting is better than the other. Lastly, the system and I seem to frequently disagree on where the middle of the lane is.
4. Audi Pre-Sense - the other night I tried to make a marginally unsafe maneuver around a car in front of me making a very slow right hand turn, and Pre-Sense did not like it one bit... slammed on the brakes & flashed warnings at me. I was like "WTF"... but upon consideration, maybe I was being a bit aggressive. Also, pre-sense doesn't like it when I follow traffic at typical NYC rush-hour distances... blinks the warnings at me all the time.
5. Side Assist - mostly works well. It warns on things it doesn't need to, but that's fine with me.
6. Rear Cross Traffic Assist - Only one real experience with it. Yesterday, I was backing out of a deli parking spot that was on a two-lane road. A car was coming in the lane that was furthest away from me (which I didn't notice, because I wasn't entering that lane of traffic), and as I was backing out of my spot, the RCTA car slammed on the brakes; for a few seconds there I was like "WTF? Why won't my car go?" and then I realized the RCTA was barking at me. I didn't feel like it was appropriate to alarm & trigger... but it erred on the side of caution.

I'm eager to hear other drivers' experience with these systems.

VipinLJ

1. I have ACC in my A7 and it works similar to how you mentioned. Same in my ex-A6. I don't think it recognizes brake lights. It uses radar only I believe. Btw, if you increase the distance to three car lengths, it works better with careful braking instead of the abrupt braking you mentioned.

3. Active lane assist in my A7 is also weird. It sometimes makes my car weave through the lane, especially within the city (not in highways) which, if I were in a car following me, would have me think the person driving my car was drunk. I use lane assist only for the visual indicator to know how close I am to the lines, if needed.

4. I've never had any presense warning in the A4 yet. I've had it once in my A6 but I don't remember whether the car stopped because the car did the braking or because I did it.

5. Side assist has always worked flawlessly for me in all my Audis.

6. In my A4, I've seen the RCTA markings pop up when I'm backing out of parking lots. But it hasn't brakes for me, mainly because I'm always stopped.

fnarq

With the ACC, do you also hear clicking from the dash area behind the instrument panel when it's toggling accel/coast/brake?

superswiss

I have ACC in my RS5. It can be controlled with the distance selector as well as the Drive Select mode. In comfort it's more relaxed and brakes earlier, in auto it should be pretty good at keeping up with daily traffic and in dynamic it accelerates more aggressively and brakes later. If you set a greater following distance it will less often use the brakes and just ease off the accelerator and let the car slow down, but unfortunately, that often means that other cars end up cutting in front of you. I pretty much always drive with it set to distance 1 and in auto mode. Seems to do a pretty good job at keeping up with traffic. I enabled the default distance setting in the MMI and have it set to distance 1, otherwise it's always distance 3 by default.

As mentioned above, it does not recognize brake lights. It only has a radar and reacts to the car in front of you slowing down. Seeing the brake lights go on doesn't mean the car in front of you is slowing down significantly enough for the system to step on the brakes, so it sometimes feels that it reacts late, but it just reacts to the actual deceleration of the car ahead of you and not the brake lights. I think you'll get used to it. Takes a little bit of retraining your brain, because we humans are trained to step on the brakes the moment we see brake lights. It's what's causing a lot of the congestion out there.

VipinLJ

I'm not sure. I haven't used ACC much since I don't feel confident letting my car drive itself. I haven't noticed anything. I will try it the next time I take the A7 out.

And yes. I agree with superswiss. I've noticed the difference in speed with which the car accelerates compared to which mode it is in.

s_Fanous

This is my biggest beef with the car. I live on a two-lane road and backing out of my driveway/garage gets the system confused with cars in the opposite direction passing by. Funny, because I completely understand the WTF moment you describe as it was my identical reaction.

exmeaguy

I find the active lane assist completely worthless because of what was mentioned about the constant swaying back and forth in the lane.

I just came from a loaded 2014 Infiniti Q50 which also did the constant swaying back and forth. I always turned this off. The one nice setting the Q50 had was called active lane warning so anytime you switched lane without a turn signal, or just drift over a line, it would beep to warn you to get back in the lane. I had this turned on all the time to warn me to get back on the road. I wish Audi had this.

Overall, I think Infiniti has done a better job of designing and execution of the driver assists.

Versprechen

I think if you change lane assist to "early" it will do less swaying. I use "late" on backroads since I hug the center line while the rest of the world is worried about head-on collisions or something and hugs the shoulder where there are far more obstacles and risks. Definitely "late" on highways. I'm definitely glad there's no beep when you drift near a line -- a simulated rumble strip in the steering wheel is smart, effective and discrete.

Oh, and I find ACC annoying to use -- in the northeast you never get a 3-car gap without it being filled and, regardless, next thing you know the car is almost imperceptibly slowing down because it sees the car in front -- which is so far ahead -- and you don't even realize it.

And I also find Traffic Jam Assist brakes way too late and hard for my taste. I haven't yet fooled with any parameters it may have.

The rest of it, especially Rear Cross Traffic Assist and the Pre-Sense City functions, I find very effective.

recreation

I've decided to stop using Active Lane Assist on a daily basis so if I do need it on a long boring road trip I won't be conditioned to ignore the steering wheel feedback.

And I agree with the comments regarding the yellow center line. I suspect the computer doesn't "see" yellow very well. Perhaps because Germany has white center lines or maybe it's just due to the reduced contrast of a yellow line. I often suspect my car is "seeing" the cut in the pavement or detritus on the shoulder instead of the yellow line, so it "sees" the middle of the lane too far to the left if it sees it at all.

I don't generally use ACC either on a daily basis because I can better anticipate the traffic ahead, which results in much less herky-jerky acceleration/deceleration and better fuel economy. I also feel that using ACC is hard on all the traffic behind you. The more people that use it the worse driving in heavy traffic will be for everybody. We'll all be accelerating up to 50 mph and then braking to a stop instead of moving along consistently between 25 and 40 mph. Still, if I'm frustrated by the traffic and want to relax a little I turn it ON.

I like to drive myself. That's why I purchased a sports sedan. But I want to be safe, too, so I paid up for the Prestige with DA features and am generally happy with that decision.

The Collision Mitigation has hit the brakes twice. Once when it didn't agree with me that the car with the turn signal in front of me was actually going to turn before I arrived at its location, and once when it saw a car coming as I was backing in a grocery store parking lot. My wife loves it. She's less likely to stomp on the passenger side floorboard.