Why merging late on the highway makes sense…sometimes

On this week’s edition of the Talking Michigan Transportation podcast, a topic that provokes strong feelings among everyone who drives: when to merge when a freeway lane is closed for construction.  

Tom Vanderbilt explained in his 2008 book, Traffic, there are two schools of thought:

The first camp - let us name it after the bumper sticker that says practice random acts of kindness - viewed early mergers as virtuous souls doing the right thing and late mergers as arrogant louts. "Unfortunately, people suck," wrote one Random Acts poster. "They'll try whatever they can to pass you, to better enjoy the traffic jam from a few car lengths ahead of you… People who feel that they have more pressing concerns and are generally more important than you will keep going, and some weak-spined schmuck will let them in further down, slowing your progress even more. This sucks; I'm afraid it's the way of the world."

Another camp, the minority camp - let's call them Live Free or Die, after the license plate motto of the state of New Hampshire - argued that the late mergers were quite rationally utilizing the highway's maximum capacity, thus making life better for everyone. In their view, the other group's attempts toward politeness and fairness were actually detrimental to all.

Gregg Brunner, acting chief operations officer and director of the Bureau of Field Services at the Michigan Department of Transportation, talks about the advantages of the so-called “zipper merge” for commuter routes. He also shares insights on the importance of driver education and public awareness for a successful implementation, as well as why the zipper merge isn't suitable for every project.

Michigan is among several states encouraging drivers to use the zipper merge technique in specific circumstances and working on creative ways to educate drivers on how it works. This Missouri Department of Transportation (MoDOT) video features adults in cardboard cars as a learning exercise on how to take turns.