It’s not “locked” to a specific distance, it’s fairly elastic and the exact follow distance varies based on speed. So, if traffic slows down, it will gradually close the gap while also slowing down. The end result then is far less drastic speed changes.

I don’t always hang out behind a semi when just doing daily driving, but I will 100% camp out behind one when pulling my trailer - massive fuel savings from reduced wind resistance.

Adaptive cruise control FTW. Matches speed with the person ahead of me (up to the max that I set) and maintains a gap that I can specify. It starts slowing down long before I’d notice the gap closing if I were doing it myself, so the +/- acceleration is a lot smoother as a result.

If there were a chewing gum with the flavour and texture of fresh kettle chips, I’d be all over that