Ironically, in spite of all the complaints here, I think the thing that is the least safe about the Safety Score system is that it incentivizes AP use in busy situations, and the characteristically unnatural and terrible driving it produces. A true 100 score for me in my 40 miles of driving today though.
Probably one of the worst incidents I've ever had on AP. There's a reason I typically only use AP when there's light traffic! Yet with the Safety Score I must do the
exact opposite. Sad.
As the description says (this was I-15S at the split to the 163):
If driving manually (which I would normally do in these circumstances; I was using AP to avoid unsafe following Safety Score dings) I would have signaled right and gotten to the right lane sooner, but the traffic in the fast lane was moving very slowly (it's always a disaster at this interchange, with people cutting in late, but normally traffic in the left lane does move the fastest, which is why I had picked it) and the lane to the right had a steady stream of cars - and Autopilot would have had a difficult time of it (but this is what I should have done, and just tried to have it find a spot - ironically I thought I would end up following too closely and wanted to wait). Going manual mode would have meant a Safety Score ding! The entire video is on Autopilot, with Lane Change Confirmation required, following distance 7. The only thing I did was reduce set speed (by about 10mph) immediately, as soon I saw the truck start to signal (I have no idea why he decided to get in so late - those familiar with this interchange know that you have several miles to get in the correct lane). And then Autopilot proceeded to ignore the truck and accelerate into it, after he was fully in my lane. I held my foot over the brake but did not use it (eventually AP applied the brakes/eased off accelerator); would have meant an unsafe following ding!
The wife was not happy - and neither was I. It would have been bad, but acceptable, if it had continued to open up space after the truck changed lanes (the correct behavior would have been for AP to see the truck signaling, and preemptively allow 2 seconds following when the truck entered the lane, which it's not capable of doing) . In retrospect I could have kept dialing back the set speed to 40-50mph, but it surprised me (I don't know why this was a surprise) that AP did not see the truck at all for a good long time. I expected it to continue to fall back, and its behavior was exacerbated by the truck also applying the brakes. Radar really doing a great job.
Perfect 100 safety score, 0.0% for everything. About 0.3 seconds following distance.
Preceding this, I had been in the right lane, but there was a lot of slow traffic which I had shifted left to avoid, and there were also disabled vehicles parked on the right shoulder which I wanted to avoid. Then the lead car started driving slowly, and then all the traffic started passing us on the right. In retrospect, should have just dealt with the traffic in the slow lane.
I blame the Prius.
Tesla should have skipped the part of the Safety Score where AP masks errors.