I think the problem with adoption has less to do with the theory of zipper merging working than local culture and traffic enforcement.
I live in Ontario, Canada, and despite of our reputation for politeness, we have some of the worst/most selfish drivers anywhere. Part of this is because there doesn't appear (anecdotally) to be a lot of traffic enforcement, so people now push the limits as much as possible, whether it be texting while driving, running red lights, tailgating or merging improperly.
The only way I could see this work where I live is if there's strict enforcement to ensure it happens, otherwise you'll see behaviours like people not letting in mergers, or a second car trying to squeeze in after the legit merger.
I live in Ontario, Canada, and despite of our reputation for politeness, we have some of the worst/most selfish drivers anywhere. Part of this is because there doesn't appear (anecdotally) to be a lot of traffic enforcement, so people now push the limits as much as possible, whether it be texting while driving, running red lights, tailgating or merging improperly.
The only way I could see this work where I live is if there's strict enforcement to ensure it happens, otherwise you'll see behaviours like people not letting in mergers, or a second car trying to squeeze in after the legit merger.