Traffic engineer: Zipper merge ‘most efficient way’ to get through congestion
Aug 6, 2024, 6:04 AM | Updated: 8:21 am
Two lanes filled with cars approaching a road closure over the hill. (Photo courtesy of AAA)
(Photo courtesy of AAA)
Nothing attracts more comments about transportation than discussing the zipper merge.
Drivers either love it or hate it. However, traffic engineers agree it is the best and safest way to merge in certain situations, primarily when losing a lane for construction.
I want to know if drivers are getting any better at it. There has been some success with the zipper merges in Everett and on Highway 8. I have found myself being cut off less lately as I use the open lane approaching zipper merges. On my last trip to the beach, the drivers on Highway 8 outside of Montesano seemed to be getting it.
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Corey Hert, the traffic engineer for the City of Everett, has been encouraging drivers to zipper merge during the four-month closure of the northbound State Route 529 span over the Snohomish River. I asked him why there is so much pushback on zipper merging.
“When you look at the typical zipper merge and getting everybody to stay in both lanes and merge at the last minute, it’s a real challenge to message because when traffic is flowing smoothly, you want people to merge over, but when it’s congested you want them to zipper merge,” Hert said.
And that is the real key. The zipper merge is only appropriate in either slow or stop-and-go conditions. If you are going the speed limit, you should merge as normal. Where there are long gaps between cars, merge as normal. The zipper is designed for intense congestion.
Hert believes the primary reason people don’t like to zipper merge is it still feels like cutting the line, but you really aren’t.
“We’re all taught when we go to grade school to get in line,” he said. “That’s the fastest way to get there. When you talk about traffic, the best, most efficient way is for everybody to stay in both lanes right up until the merge and then everybody merges at the same point. It’s the most efficient.”
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And please don’t take it upon yourself to block others from merging this way. When you stick your hood into the open lane, you only create road rage and you are making the merge worse.
“There’s no reason to be aggressive,” Hert said. “If everybody just comes up to the merge point together, go every other and take turns, it really works well.”
Merge late. Cooperate.
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