3 was not much of an assumption. Roads are very rarely exposed to their peak capacity. 99.9% of the time they have substantial capacity to absorb excess traffic. Your assumption that they cannot is that 0.1%.

Once the motoring public at large understands the method and utilizes it, the only way it doesn't minimize t

False. Patently false. The degree of control required to prevent stoppages is not available to individual drivers. To avoid hitting cones, drivers near the end of the closing lane have to make rapid changes in speed to ensure they are lined up for a zipper merge. That means hard braking, and that braking ripples through to everyone behind, in both lanes. Zipper merging is the root cause of stop and go traffic.

That hard braking isn't required when zippering at the beginning of the closure, because there is no hard obstacle to hit in the open lane.

At best, this zipper-at-the-end method "works" not by achieving any traffic benefit, but by setting the expectation for other drivers behavior.

The alternative to zipper-late is "no passing in work zones". Your position is established at the time you enter the zone; you have between that time and the obstruction to merge, but you may not pass someone in the adjacent lane. There is no longer any benefit to racing ahead to the end of the lane. The zipper merge occurs shortly after the lane closure.

The upside of zipper-late is that there are fewer opportunities to be pissed off at "cheaters". It is psychologically better. It reduces road rage.

The downside of zipper-late is everything related to traffic. It introduces far more disruption. It needlessly turns free-flowing traffic into stop-and-go. It endangers workers at or near the closure.

"No passing" is objectively better for traffic before and during the closure. It increases speeds and thus throughput. But it also makes it easy for everyone to identify and be pissed at "cheaters". Those cheaters induce road rage, so we can't have the superior traffic method. Instead, we have to normalize cheating and tolerate worse traffic.

We tolerate slower baggage handling and longer walks through the terminal when they move the baggage carousel further away from the gate, but we complain much less when they do that. Zipper-late works much the same. It worsens traffic, but trains us to be more tolerant of worse traffic.