The zipper merge works theoretically on paper, if everyone is travelling the same speed but as we all know that doesn't happen. On an Interstate, where the speed limit is 70, you'll have people driving 65, 75, 80, 90, and the Ohio State Patrol posts pictures on average of 3 times a week of a few cars they caught running over 100 mph. Tuesday, they posted a picture of one the caught running 107 mph on I-71.
Here in Ohio, there is no law on zipper merges, only recommendations, can't speak for other states. Those recommendations are from engineer's setting behind a desk looking at computer generated examples, not in the real world. I know, I worked for ODOT for 32 years. Get those same engineer's out on the job in a real world situation and they are lost.
Let me enter different vehicles running various speeds in that program, to merge in, here a mandated 2 mile transition area. Bet it won't look the same. I've seen enough rolling road blocks by semi's to keep the one clown passing everyone right up to the lane closure, then a trucker beside him will slow a bit and let that truck in. I've seen people driving down the paved shoulder to pass slowed traffic in the same situation. There's a 99% chance they are not in any bigger hurry than everyone else travelling.