This kind of merging - in heavy traffic - is a safer and superior method to get everyone through the bottleneck. According to studies across the country, the zipper merge can improve traffic backups through a construction zone by 50 to 75 percent.
Computer simulation models and, perhaps more important, real-life application has proven the zipper approach is superior but — and here’s where the psychology and change management come in — places that have implemented the approach have also struggled to have drivers “get it” and to consistently follow the approach. Consistency is key here because if a driver doesn’t get it then road safety (and sanity) are at risk.
Part of the problem is awareness. Not many states vocally encourage the zipper merge, so every newcomer has to learn the rules. But the other half is guilt and fear. “I don’t know if it’s a Minnesota thing, or an education thing, but people just do NOT zipper merge,” one sad driver wrote on a recent DOT survey. “And they get irate at the people who do. Seems that the choice is to either sit in line like a lemming, or do the zipper merge and endure the wrath of those who have been sitting in the line.” Another wrote, “Maybe it just feels wrong? I feel guilty about passing all those people and merging at the end.”
Perhaps one day... in the distant future... we'll learn that zipper merges help us all.