Comments on: The Zipper Merge and Civil Society

By: Beth Hawthorne

Beth Hawthorne — Fri, 29 Apr 2011 03:43:52 +0000

Having driven in Germany for three+ years I learned the benefits of the zipper merge. This can be done at a high rate of speed if everyone waits till the merge point and allows room for the next guy. I have tried to explain to friends and family that when everyone takes turns and the me first concept is bypassed traffic can keep moving with little disruption. You can get more people through a traffic light where on the other side it merges into one lane if you use both lanes and have two lines of ten who can get up to speed more quickly and zipper merge then if you have a line of twenty going single file. Those who try to prevent the late merges only create the merge point sooner and hard feelings along the way.

By: DoctorJay

DoctorJay — Mon, 13 Sep 2010 12:27:13 +0000

i just got hit at the merge going into the Holland Tunnel in NYC. There are 2 lanes going into the tunnel and a guy came up from the 3rd lane, which wasn’t and jumped to the front of the turning traffic and attempted to squeeze in. It was a tight fit and as soon as traffic started moving again he swiped my front bumper, pulling off the rubber and denting his car. We parfked and yelled at each other for a few minutes before leaving in a huff.

I think there’s a difference between the zipper merge when you have 2 lanes going to 1, and the jumping of a merge, when a driver purposely drives around the line of cars and tries to squeeze in from a lane that isn’t part of the merger.

By: Daniel

Daniel — Sun, 05 Sep 2010 19:30:11 +0000

The problem with early merging is that the “naturally occurring” gap keeps moving back progressively as drivers merge. In theory, you end up with a long queue that forms well before the merge sign. Or, if all drivers merge exactly at the merge sign, then, in theory again, this is the same thing as merging at merge point - only the location changes.

When in a closing lane, I always try to match my speed with the traffic in the next lane (unless it’s down to a crawl, but then I still slow down, I don’t “zip” at high speed) and merge as close as possible to the merge point, but not too close so I don’t have to slow down and create too much of a disturbance.

Oh, and I also watch for lane vigilantes. They tend to make things more complicated.

By: Josh R

Josh R — Fri, 03 Sep 2010 02:18:21 +0000

Sorry Elliott, but research has shown the reverse to be true, using both lanes until the merge and then “zippering” the cars into one lane is better. The problems arise when everybody but a few merge early, and then people play lane cop trying to not let the “late” mergers in. Every lane closure here in MN these days has signs saying “Use both lanes until merge point.” in an effort to break people of the habit of early merging, but it’s an uphill battle because everybody thinks they know better then the traffic engineers who study this sort of thing for a living.

Personally I merge early, but solely to avoid the irrational anger and potential violent outbursts of the lane vigilantes.

By: Ryan

Ryan — Fri, 03 Sep 2010 00:25:59 +0000

Elliot,
Perhaps you should give Mr Vanderbilt’s book a read. You may reconsider your hostile sentiment to those who merge late.

By: JJM, traffic engr.

JJM, traffic engr. — Thu, 02 Sep 2010 22:29:15 +0000

Mr. Mason, merging early works well at lower traffic volumes, but once traffic starts to back up, about 15% more traffic can get through if drivers cooperate, use both lanes to the merge point, then take turns.

Now, isn’t taking turns civilized behavior?

By: Elliott Mason

Elliott Mason — Thu, 02 Sep 2010 15:34:14 +0000

Merging early makes traffic move better because you can move in when there’s a gap naturally occurring, instead of making the traffic you’ve pointed your nose at stop JUST for you to make a hole. That’s why queuejumping idiots who zip up the right lane because they’re too important to act civilized ruin it for the rest of us. :->

By: Robyn

Robyn — Wed, 01 Sep 2010 18:47:06 +0000

Apparently, we are not so civilized in the midwest. Those who speed ahead and then expect someone to allow them in at the cones or barrels will get dirty looks at the least and most people hug bumpers at that point in an attempt to keep them out as punishment for not merging sooner.

By: Bob

Bob — Wed, 01 Sep 2010 15:28:21 +0000

I remember in 2003 approaching a merge with a friend who is a police officer in the vehicle. He told me I must by law merge as soon as possible, and my driving down the right side to the absolute beginning of the merge makes traffic go slower. I told him he was nuts. A couple years later I read “Traffic”, and can now rest assured that I know how to merge. Although a couple weeks ago a traffic vigilante tried to take my front end off by swerving to block two lanes so he wouldn’t have to merge again.

By: Eric

Eric — Wed, 01 Sep 2010 13:27:24 +0000

In Colorado, they put up notices of lane closures miles in advance. The people here are so “civilized” (read stupid) that as soon as they see that the right lane will be closed in 1 mile, 95% of the cars move to the left lane, which would work fine, except for the 5% of people who continue along in the right lane until the merge actually occurs. Because the zipper merge is still occurring at the merge point, traffic moves just as slowly, but the people who merged early sit in a mile long lime while the “uncivilized” (read smart) people get to continue on without much delay.

Lesson: don’t merge until you have to. Then take turns.