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A thousand miles of AP on 2019.32.12.2


Active Member
Jun 28, 2019
Talent, OR
Yesterday we finished a 1200-mile round trip to Oregon and back home to Sacramento. Nearly the whole trip was on I-5 (that's "the 5" for those of you from SoCal). I'd estimate that we used some level of AP on about a thousand of those 1200 miles. So I thought I'd share some thoughts. Read if you're interested. Comment if you're more interested. Or ignore if not.

First, the bad (I'm an optimist, so I'd rather end on the good):
  1. Bronco Mode. I named this based on my wife's complaint as a passenger--she said she felt she were riding a wild bronco. This happened several times, and the conditions were consistent. We'd be on a curvy stretch of the freeway in the mountains. We were in lane 2, approaching a slower semi in lane 1. It was plainly clear that we would pass the truck with no trouble. Well, plain to me. The car would suddenly brake--not super hard, but enough to nod our heads forward and press our bodies into our seat belts. Then it would realize the lane was clear, and accelerate. Then slow. Then accelerate. Hence the bronco comment. The car seemed to be showing doubt about whether the truck was in our lane. It clearly was not. In straighter conditions, this was never a problem.
  2. Wiggle Your Hips. The Model 3 is a sexy car, but I do not want Wattney wiggling from side to side. This also happened several times. The car would begin a lane change, then have doubt and move back, then resume the lane change. Sometimes there would be several wiggles before it decided one way or the other. Most times I wrested control, embarrassed at how this looked to fellow drivers. This was usually when there was another vehicle in the intended lane. I'm all for the car changing its mind when conditions change abruptly, but this indecisiveness is annoying. After a few instances, I saw other nearby cars just plain back off, likely afraid of the drunk behind the wheel of our car.
  3. Imaginary Friends. (Or Enemies.) There were a few instances of this. I'd be rolling along on NoA, nobody nearby in any lane. But way ahead I'd see traffic merging from an on ramp, or a slow truck, so I'd turn on the left indicator to tell the car to change lanes. Most times this worked fine. But a few times the lane would shade blue, we'd start to move over, and then the car would fairly gently move back to the original lane. One time there was a screen message that said (approximately), "Auto lane change cancelled." I could see no reason it would have bailed out.
The good:
  1. We made this same trip about six months ago. There were several times back then where the freeway would be curving left as a right exit headed off. The car would hesitate, as if uncertain whether to continue on the freeway or take the exit. (The NoA route was to continue on the freeway.) My guess was that its attraction to the exit was that it was actually a straighter path than staying on the freeway, even though not the right path. Anyway, this never happened on the recent trip. Yay!
  2. With the exceptions mentioned above, in general automatic lane changes were smoother and, well, more human than in previous releases. It seemed more confident. It adjusted speed up or down to match traffic in the intended lane, and did so nicely. In fact, it solved problems well that appeared more difficult than the ones where it wiggled (#2 above). Yay!
  3. It seemed to be looking farther ahead than in the past. Before there have been times we were approaching slower traffic, and the car wanted to maintain its set speed until uncomfortably late before slowing for traffic. On this trip the slowing began earlier, and was thus more gentle. Related to this, it seemed to be making decisions earlier about changing lanes to pass slower traffic ahead. Yay!
So that's my trip report!
Thanks for write up. I also experienced most of what you have. I agree AP, NOA, etc are getting better to mimic what decision I would have made. Majority of the time its about right, but "bronco mode" also happens on the streets, usually when car slows down, then stops and slows down again rather than one continues brake sequence. Enjoy long drives to come!