Zipper merge is best merge you dingus.
Yep. Science says OP is wrong: https://www.acg.aaa.com/connect/blogs/4c/auto/zipper-merge-keeps-traffic-moving
ISTR there being some indication that as speeds increase, merging further away from the “final merge point” can help, but that’s for designing roads with permanent lane reductions, not for temporary lane closures due to construction, accident, etc. But, I also couldn’t find that science when I looked for it.
The problem is these people won’t zipper merge most of the time. I always leave 2 car spaces, and the asshats want me to come to a complete stop before they do.
just let them merge for fucks sake
It’s weird when people think getting places fast or first is the point of driving.
“Safe” is the word you’re looking for. Then, as fast as safe will calmly allow.
Learn what zipper merging is you fuckin potato.
Or do you want backups to take up twice as much space as they need to? It’s about efficiency. If everybody zipper merges, you still get your fucking turn.
Yeah people like this are fucking idiots. Just let the dude over it’s not going to slow you down it’s not going to stop you shit if it cost you 15 seconds oh my god what the fuck ever. People are fucking retarded when they think that they have the right to own a lane.
Right! People get so crazy impatient and entitled when they enter a vehicle.
If it’s a lane closure, yes, you zipper merge at the end-- imo, because you need visual confirmation of what’s happening but also because it’s predictable and usually both lanes are already matching speeds and zipper merging ahead of you. There’s no need to complicate things with an early swap. Granted, I rarely see a lane closure warning more than 100 meters, if at all… in my tiny car, the best indicator that we’re merging is sudden lane changes of everyone in front of me.
Where I draw the line is when there’s an exit only lane on a freeway and people are zooming along and suddenly want in. Did they jump into that lane just to get ahead? Or are they a helpless victim of circumstance from the latest onramp and unable to merge until now? I let them in, but I’m usually bitter about it.
That sign was for him and for you to prepare to leave the room for a car to zipper merge when the time comes, dummy.
Jesus, the only thing worse than incorrect is confidently incorrect.
Nah, they read it. Just want to cut in line because they feel more important that everyone else. It’s pretty obvious when somebody pulls that shit on purpose. Then others you can tell they are oblivious. I usually let them in either way because I try to not get annoyed by the little things in life but sometimes it’s hard to not get annoyed…
I think people forget that nobody is racing you. If someone merges into traffic in front of you, theyre not winning and youre not losing. It’s all OK. You dont have to be upset.
I’m a tax payer and I’m going to drive in all the lanes I paid for then zipper merge when needed. If we all pile up in one lane because we are too collectively stupid to use all our lanes and zipper merge then we are the traffic we deserve.
Bruh, just let them in. It costs you all of 3 seconds, at will prevent a road rage incident. If you got ac, we all getting to the same place at roughly the same time.
I don’t really understand what zipper merging has to do with this if the issue is that they waited until the very end of the lane to try and merge and now have to do it immediately. (At least that’s what I assume is happening based on the description)
Zipper merge is intended to happen at a gore point. Zippers aren’t randomly closed at various sections and open at others, they close from one end - that’s where the merge is. It’s very literally like a zipper.
Ohh okay that makes more sense
I don’t know about you guys, but the teeth an my zipper are lined up ahaid of time and “traveling” the same speed. I would be fine with zipper merge if that where the case, but every time i am in the open lane and the other one closes there are 10 jerks who sped to the end and now feel i should have to come to a full stop and let all 10 get in front. Also, my zipper gets joined at the botom and the “merge” point travels back up the the path. we are all going to sqeeze into one lane anyway. Don’t care where it happens as long as everyone maintains speed. If you expect me to stop my lane so 10 can come from yours we have a problem.
If everyone stayed in the lane that’s about to close, your scenario wouldn’t happen. The issue isn’t the people going all the way to the end to merge, it’s everyone merging beforehand that causes the backup.
Traffic waves in that scenario come from people merging. If everyone merged at the end, there would be a small, consistent slowdown there. One small wave being reinforced over time. But, because everyone in the lane about to close merges as soon as they can, there are dozens of waves being generated all at once, which causes the stop-and-go effect. And as the backup becomes worse, more people start merging earlier, causing even more waves and more backup.
The issue is that in backed up traffic, not zipper merging results in a single lane of cars that takes up twice as much road space as zipper merging.
Perhaps the issue is zipper merging not being taught in drivers ed, idk.
It’s taught, but the concept is counter-intuitive, goes against American etiquette for queuing, and puts all of the risk for getting stuck on the driver doing the correct thing (going all the way down to the merge).
Then it’s not properly taught. You’re still queuing, and if everyone is taught how to do it correctly and is executing it correctly, it works well and everybody gets their turn. Hell, you don’t even need everybody to do it correctly, just most people.
If people don’t fully understand the concept enough to recognize that they are still in line and get their turn, then they were not taught the concept correctly or are not smart enough to be driving a vehicle.
If things are flowing properly and maintaining proper space both lanes would be combining at the end where the closed lane cuts off, they would be moving at the same speed by necessity. No one would have space to zoom to the end because it would be occupied.
Merging at the last minute is the correct way to do it.
Zipper merge, you fucks!
I would agree with this if literally anyone else knew how to zipper merge
The solution is educating people about zipper merging, not getting angry at those who actually do it.
Here in Poland it works quite well, at least when the merge is expected.
But we have signs reminding people of that and they also display this kind of driving tips on info boards on motorways when there is nothing more important.


We only started seeing signs in my city telling people to zipper merge, but I was never taught it in driver’s ed, and we really should be.
I wish we had better signage here like you have in Poland.
Nothing about the zipper merge says, “last minute”. It is wholly and entirely about matching speeds and making room.
Guess what dictates the speed of the lane that gets to travel forward? The amount of traffic that gets to travel… in that reduced number of lanes.
The people racing to the end of the closing lane are doing nothing but increasing traffic density, which directly hurts the effort of zipper merging. If it’s going from two lanes to one, the density MUST halve somewhere if traffic is full. That’s never going to happen at full speed if there are assholes wedging in at the last second and pushing traffic density past what people comfortably go full speed at.
Hint: it is not bumper to bumper on the highway.
Again: Merging at the last second does nothing but push traffic density up. Often past comfortable densities, which will slow traffic. It’s the exact same reason rolling stops happen even without traffic accidents or lane closures in dense traffic.
Last minute is absolutely part of it. Use the available queueing space to keep congestion from spreading. I don’t know where you drive where bumper to bumper didn’t happen, though.
thank you. the math agrees, too. zipper merges are the way to go!
Gave a ride to someone who for one hour kept bitching about drivers who use zipper merge properly. didn’t want to tell him he was wrong.
he was so convinced and fuel by hatred of better drivers.
Depends. If there’s lots of traffic, yes. If it’s sparse enough that you can merge without slowing people down too much, just do it early.
Yeah, that’s the big asterisk on the “zipper merging is more efficient” premise. It assumes that things are already bottlenecked. If you have the space to merge early without slowing down, you do that. People trying to force their way in at the last minute (when they didn’t have to) is one of the things that triggers the bottleneck in the first place.
I’ll merge early but also try to go a bit slower than the person in front of me to open a gap which allows me to absorb some of the traffic wave (where flow alternatively speeds up and slows down from people trying to get up to speed only to have to slam on the brakes because some car ahead wasn’t going fast enough to maintain that), as well as leave space for others to merge at speed.
Though I sometimes close the gap if I notice people pulling into the right lane to try to skip the line.
K but people don’t tend to complain about those driving down the empty lane if there is no bottle neck.
Obviously if you’re racing down to cut someone off, that’s just as rude as any unsafe merge, but thats not unique to zipper merging, so is it relevant?
Zipper merge is always the most efficient if people dont prevent merges, regardless of road conditions. It means both open lanes are used to move cars forward until the last moment when they cannot. “Move over early” means less throughput in the system, no matter “how open” one lane is at some point.
By blocking merges, you causes braking, which is what causes traffic. You framing people driving efficiently to prevent traffic as “people trying to force their way in last minute” means its you creating traffic, not them.
You’re arguing from a sense of moral suppority, I.e “I got in line early, you should have to,” not from a sense of efficently moving cars down a road.
It’s rare, but I think they’re referring to when it’s open enough and running at optimal speeds. It happened the other day on a side street during an off hour, the free lane couldn’t cut to the front without going like 70mph in a 40mph zone.
Of course a muscle car did just that, but still.
No.
Throughput is determined by number of through-lanes and the speed at which traffic is moving. Period. Completely.
Filling the merge lane when traffic is already slow does nothing but drive density up, which slows traffic further.
Sure, YOU might save some time by passing a bunch of cars, but it DOES NOT IMPROVE THROUGHPUT.
Zipper merging is about NOT having an area of abrupt speed change. It is not about using up a lane that is going away. Period. Ever.
It’s the same as an on-ramp: If you’re speeding up just to slam on your brakes to merge, that’s not zipper merging!
Someone made a simulator for these scenarios where you can adjust on driver behaviour and see metrics in what is most efficient.
At a respectable speed though, merge lane is not a passing lane. My rule is whatever speed can be maintained stay with the car speed in the lane to be merged into, jamming the front punishes everyone cueing properly.
The the merging lane is empty for a half km, then it’s proper to drive to the front and merge. If you just drive slow, then you’re a problem for the sake of being a problem.
Drive to the front, match speed, zipper merge. It isn’t hard.
Depends on what you mean by “the front”. Too many people do not know how to look thousands of feet down the road. Probably why so many merge too early.
The assholes that also do not know how to look thousands of feet down the road fly to the end and cram in, which does nothing but further reduce throughput because it slows the lane people need to merge into.
That is literally what a zipper merge is, and what you are supposed to do. Go to the end and merge. If they are “cramming” in, then the people in the lane are not doing their part either, because you are supposed to let people merge.
When people properly zipper merge, traffic will keep flowing. Your complaint about reducing throughput is a “well of fucking course it will” because you’re putting more cars through the same space regardless of where they merge. People who slow down with hundreds of meters of space, then stop and wait for someone to let them in makes the problem worse, not better.
That was the respectable speed part. I agree too slow is also an issue.
Fair.
Yes before the lane is closed. They are not doing that.
No. You are explicitly supposed to go to the very end of the closing lane, and then merge, not before it closes.
Well a closing lane would be marked with an arrow pointing to the lane next to it, and if it’s closed it’s a red X. You merge before the red X. I don’t see a closing lane the same as a closed lane. Maybe it’s a translation thing. And every country is different.
There’s Zipper Merge, and then there’s “I’m more important than everyone else, so I’m going to the front of the line and force my way in.”
See, the single file line continues to move if everyone gets over when the sign clearly says “Lane Ends Ahead Merge Now”. It may move slowly, but it moves. If people pass everyone in line and speed ahead to force their way in, the single file lane then has to repeatedly stop to let those people in. The people who followed the road sign and moved over (by zipper merging at the right point) are now being punished, forced to repeatedly stop, and keep getting pushed farther and farther back by those prima donnas whose trip is way more important than everyone else’s.
You can keep yelling “ZIPPER MERGE!”, but those assholes saw the same sign I did telling them that they should move over, but they didn’t. Now they can wait.
I don’t understand people like this. There are two lanes. Use them. If everyone merges into one lane over two miles it’s going to create a HUUGE backup. Use both lanes, zipper merge at the end. Stop being stupid and use your brain instead of your emotions.






