Zipper merge is an excellent metaphor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yesterday I learned a phrase which is an excellent metaphor – zipper merge. It is courteous adult behavior described in a thirty-second YouTube video from the Utah Department of Transportation, which says:

 

“When two congested lanes on a Utah roadway become one, we use the zipper merge. Vehicles should use both lanes right up until the merge point, then take turns converging into the open lane – just like a zipper. Drivers in the closing lane must use their turn signal before moving over safely. Drivers in the open lane must let one vehicle move over in front of them. This helps reduce congestion by as much as 40 percent. And it’s the law.”

 

Another similar video from the Idaho Transportation Department titled How to Zipper Merge says:  

 

“You see a ‘lane-closed sign up ahead and the lanes are merging. So when should you actually merge? Well, the answer might surprise you: You should stay in your lane up to the point of merge. It’s called a zipper merge and it’s not only safe but encouraged. Each car takes turns easing into the open lane. This keeps things smooth and fair for drivers in the continuing lane and the lane that’s ending. So next time you see a lane-closed sign, don’t stress. Just merge when it’s your turn.”

 

There is a section titled The Zipper Merge – Research and Applications in Chapter 2 of the November 2017 U.S. Department of Transportation publication titled Recurring Traffic Bottlenecks: A Primer - Focus on Low-Cost Operational Improvements (Fourth Edition). It also is discussed in a web page at trafficwaves titled Merging-lane traffic jams, a simple cure. And another web page at Academic Dictionaries titled Zipper merge says Kevin Lerch claimed to have coined the term in the late 1960’s. I ran across it in a not-safe-for-work YouTube video titled Lewis Black reads a rant about Rhode Island bridges.

 

The zipper image was adapted from one at Openclipart.