Thanks @DocScott, it's useful feedback that TACC handles the merge lane well. Perhaps that might encourage hypermilers, folks who want to drive nearer to the speed limit, etc., to use it more often.On a 3-lane (or more) highway I drive differently in a Tesla with AP than I do in an ICE car without.
In an ICE car without AP, I like to drive in the middle lane, because the merge lane is annoying. Because the middle lane generally moves a bit faster than the speed limit, I drive a bit faster than the speed limit (maybe 5-10 mph faster).
But with TACC, I like to drive just a bit above the speed limit. I like the better efficiency than driving faster...I've commented elsewhere on this forum that I do achieve the rated range in summer, and that's part of the reason why. It's also nice knowing I'm not at risk of tickets.
But to do that, it means I've had to re-train myself to drive in the merge lane! TACC has no problem with dealing with the modest speed adjustments needed as people ahead of me merge on and off. And travelling at the speed limit + 2 mph is acceptable in that lane.
So I agree with @JeffC. I think a lot of Tesla drivers have made the first part of my shift in driving strategy, using a bit slower speed than they would in a car without AP, but haven't figured out that they can do so in the merging lane.
Again, the principle is to keep traffic flowing smoothly and avoid going too quickly or slowly for conditions, including the speed of cars nearby.
I do understand the idea that the middle lane is a good place to be for the good reasons you and others gave, but it should be done in a way that is similar to the speed of other cars in that lane.
Also agree that the physics of drag means that driving slower will be more thrifty with energy, especially at highway speeds.
Therefore driving relatively slower does usually result in greater driving range. Since drag is a cube of velocity, the effect goes up quickly at higher speeds (say, more than 70 MPH), even though Teslas have very low drag coefficients.