I was there a year ago in a rental Tesla with just basic AP and it did fine on Highway 17. If you stay between the lines that's success. What's special about how "FSD" handles this?
Staying between the lines is the most basic of successes. The most objectionable issues camp up when going around a sharp turn, typically labeled 40 mph advisory.
The old behavior was to slow down for the turn but to do it much too late and too large of a speed delta in just a second. It was unsettling to the riders and to traffic behind. The addition of brakes at the turn entry also caused suspension compression so the bump steer would send the car further wide in the turn. It was quite unsettling. I typically set my speed to 58-60 and it would often slow abruptly to 42 for the slowest turns. Also those turns felt like a series of decisions, so the wheel would take a set, then jerk to a new set, again and again as if the curve had no smoothing.
The new behavior is to maintain overall slightly lower speed, but now to maintain that speed through most corners. The application of brakes if any comes very slowly and sooner that the turn event itself, so the suspension is already compressing by the time the car is turning. Through the turn itself it feels like 1 smooth curve with minor adjustments instead of a series of points connected by straight lines.
The old behavior was to constantly shift maximum set speeds, depending on the FSD stack (most of 17) or the highway stack (at each end) I found myself constantly trying to adjust the speed to the point of absuditity. Now I have no control of the speed over 17 itself (fsd stack uses MAX settings), but because the driving is smooth and with the flow of traffic I don't feel the need to change it either. The car will go about 15-17 mph over the limit max, but more often cruises about 7-8 mph over the limit,a nd slows down or speeds up with traffic or danger.
The biggest objection is that it wants to cut the corners, and that sometimes it will catch the Truck 35 mph speed limit and misapply that. Still even showing 35 max, it was cruising at 52mph until I applied the accelerator to override the slower speed.
It no longer wants to select any given lane at any time. It really seems to track both fast and slow lanes speed very well and merge into the fast lane only when needed. Then it smoothly merges back into the slow lane. No longer is it getting into the fast lane, then slowing for a corner and getting passed on the right.
When it is time to zipper merge, it is now aggressive without being too extreme, very much like an average human merging.
