Variable ACC trailing distance

[Ray B]

I have the ACC trailing distance set to one bar, and this seems pretty comfortable for me about 90-95% of the time (I'm guessing it is normally about 2 seconds of separation to the next car ahead). But I notice on occasion - mostly off the highway - the gaps seems different. It either gives a really long gap (dunno - maybe 3+ seconds?), or more disconcertingly gives a lower gap (guessing ~1 second?) - enough that I feel like it is close to tailgating and I have to disengage it.

I had a hypothesis that is was doing the occasional shorter gaps for darker cars that tended to blend into the surroundings, and the white cars tended to be kept at the longer distance, but I think I may be imagining that (confirmation bias). It doesn't seem to be related to a certain road or speed, just kind of random occurrences I guess.

Anyone else notice this kind of ACC time gap variability from time to time?

 

[jdonalds]

The gap varies based on speed. There is no way for the radar to see the color of a car.

 

[Ray B]

I am talking about roughly uniform conditions for the daily commute - suburban roads at 35-40 mph. Most times the gaps is what I would call 'standard' and then there are some odd instances where it is leaving a curiously long gap, or a really short gap, again at the same range of speed. In all cases the dashboard shows that the ACC recognizes a car.

Not bothered by it - just curious if others have witnessed any similar ACC anomalies.

 

[craze1cars]

The only thing I can contribute is that oddly enough I’ve always found the car has a harder time “seeing” semi truck trailers in front of me vs regular cars or even motorcycles.

Just occasionally, not always. And sometimes it reacts to long shadows early or late in the day.

Same for my 2016 Civic and my Clarity.

 

[KentuckyKen]

Mine reacts pretty consistently. I think I’m blessed with a well behaving Clarity that seems to like being in the middle of the bell curve.

It is supposed to maintain the following time interval by increasing the following distance interval as speed increases (p 410).
Mine seems to do that but I’ve only “clocked” it with the old one-thousand-one, one-thousand-two human OEM timer which admittedly is not as precise as it once was (or ever was).