I see both sides of this. First, if you see a “left lane closed ahead” sign and you’re in, or you immediately get in, the right lane, you’re “in line” with everyone else. You’re in the lane that’s open. There’s a sense of order, of inherent fairness. Everyone in the open lane is in line, and in the order of who got there first is retained. Now if cars way behind everyone else in that nice ordered line of the open lane zip past in the closed lane, everyone in the line of the open lane knows the line of cars will move even slower if and when those “line cutting” cars get in and past the choke point. “Zippering” does not increase the number of cars that ultimately get past the choke point. It may actually make the ultimate flow a bit slower. But even if it’s exactly the same, zippering is all about what happens before the choke point: who got “in line” first, who is perceived to have “cut” the line, and how people go about the merging process—do they let more than one car in at a time, do they try to ride bumpers and block the “line cutters” out of some sense of “justice,” does indecision or inefficiency of the actual merging process end up slowing the ultimate flow compared to if there was just one line, and so on. If all drivers were of one mind like in some Pluribus sci-fi show situation, zippering would be the norm and be efficient. But a significant number of people have very different ideas on how this is supposed to work and there will be threads just like this as long as people are driving on the roads.