# Is the resistance to the zipper merge a failure of signage?
**URL:** https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005
**Category:** In My Humble Opinion
**Created:** [July 13, 2023, 9:23pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005 "2023-07-13T21:23:57Z")
**Posts on this page:** 20
**Page:** 2
### Author:  [@Digital\_is\_the\_new\_Analog](https://boards.straightdope.com/u/Digital_is_the_new_Analog)
#### Post date: [July 14, 2023, 12:28pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/21 "2023-07-14T12:28:17Z")
The first several times I saw the subject line, I assumed this was about clothing, because I read it as “a sign of failure” not “a failure of signage.”
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### Author:  [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)
#### Post date: [July 14, 2023, 12:52pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/22 "2023-07-14T12:52:36Z")
> [@Gorsnak](#):
>
> When this discussion on zipper merging arises in my local subreddit, r/Saskatoon, people will frequently comment, “I don’t know why people don’t understand how to zipper merge, because they do it all the time at [Spadina and 25th](https://www.google.com/maps/@52.1315089,-106.6514563,192m/data=!3m1!1e3?authuser=0&entry=ttu).”
I think that’s different, because it is the junction between two different streets. Plus, there is no possibility for drivers on Spadina to pass a line of cars on 25th as part of the merge. That’s the main psychological barrier to zipper merge, as @Kropotkin 's comment mentions: the sense that someone else is getting ahead of you by passing on the other lane.
The Spadina example is “my turn, your turn”, which doesn’t raise that issue.
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### Author:  [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)
#### Post date: [July 14, 2023, 12:57pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/23 "2023-07-14T12:57:13Z")
> [@Dr.Strangelove](#):
>
> A single lane at 60 mph is better than two at 30 mph, since individual cars will spend less time on the stretch.
But a single lane at 60 mph actually has less than half the capacity of two lanes at 30 mph because of the extra following distance required. I’d need to look back at the statistics, but overall the maximum throughput of a single vehicle lane at around 2,000 vehicles per hour is achieved at speeds in the 20-30 mph range. Above that speed and the extra spacing required to maintain a safe stopping distance counteracts the increased speed.
Thus, you won’t be able to get that single lane moving at 60 mph if two lanes are already only moving at 30 mph, at least not after slogging through a long backup. Then the advantage is back to the two lanes with the latest merge possible, because it makes the backup half as long (even if the number of vehicles is the same).
This is how I always viewed the purpose of the zipper merge. It can’t magically fix congestion when the number of vehicles exceeds the capacity of the road with reduced lanes. It’s to prevent queue jumping by using the lanes to their max until the merge point. After all, if everyone “behaved” properly and merged as soon as they saw the “left lane ends ahead”, say two miles up the road, then that’s no different than if the merge point was itself two miles up the road. It’s not the queue jumpers causing the backup, it’s the number of vehicles.
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### Author:  [@Horatius](https://boards.straightdope.com/u/Horatius)
#### Post date: [July 14, 2023, 1:46pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/24 "2023-07-14T13:46:07Z")
> [@crazyjoe](#):
>
> Unfortunately, this is not what happens. Instead, the ass-clowns in the “open” lane use it as an opportunity to shorten their journey by rapidly passing all the cars in the “waiting their turn” lane. If the ass-clowns would just get on board with actually using the disappearing lane with courtesy, zipper merge would work.
But that also requires the “assclowns” in the “waiting their turn lane” to stay far enough behind the car in front of them that the other lane has a place to merge into.
And this, ultimately, is why zipper merges fail so often - it requires all drivers in both lanes to work cooperatively to make the merge work, and we know, for a fact, that at least some percentage of drivers in both lanes are assclowns who don’t want to help out their fellow drivers. It doesn’t take many assclowns to fuck it all up.
And assclowns breed - when one driver fucks things up, other drivers get frustrated, and then are more likely to act in a selfish manner, thus fucking things up even more.
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### Author:  [@pulykamell](https://boards.straightdope.com/u/pulykamell)
#### Post date: [July 14, 2023, 2:07pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/25 "2023-07-14T14:07:01Z")
> [@Northern\_Piper](#):
>
> This is the answer. Different signage won’t do anything for drivers who think the ones who zip to the end of an empty lane are cheating.
Here’s a solution I saw in the comments of a YouTube video on zipper merging: don’t say which lane is closing ahead. The commenter said they didn’t know whether it was done on purpose or the road crew forgot, but both lanes were used to the merge point and it was glorious.
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### Author:  [@Icarus](https://boards.straightdope.com/u/Icarus)
#### Post date: [July 14, 2023, 2:23pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/26 "2023-07-14T14:23:13Z")
Another unstated issue with the zipper effect is semi-trucks. Zipper-ing CAN work really well when all vehicles are relatively the same size, but a semi-truck poses an additional challenge in either lane. Generally they move to the right lane early, having the advantage of the driver sitting higher up they can see farther ahead and anticipate better. But the merging vehicle may create difficulty figuring out where to zipper-in relative to the semi.
An overall solution I see would be a human at the end of the merging lanes directing cars into the zip, (I’m sure I’m not alone in observing the seemingly abundant road workers not really doing a whole lot, surely assigning one to direct traffic would be an efficient use of resources) “You go, now you go, now you…”
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### Author:  [@Horatius](https://boards.straightdope.com/u/Horatius)
#### Post date: [July 14, 2023, 2:25pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/27 "2023-07-14T14:25:09Z")
> [@jjakucyk](#):
>
> After all, if everyone “behaved” properly and merged as soon as they saw the “left lane ends ahead”, say two miles up the road, then that’s no different than if the merge point was itself two miles up the road.
Well, there is a difference. If you’re merging at the physical merge point, you have a hard limit on when you can merge. If you don’t have a place to merge, you either stop or hit something.
Merging earlier, at a “virtual” merge point provides some flexibility. If there’s a bunch of tailgaters who refuse to leave an opening to merge into, I can speed up or slow down to find a different spot to merge, hopefully without having to slow down too much.
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### Author:  [@WildaBeast](https://boards.straightdope.com/u/WildaBeast)
#### Post date: [July 14, 2023, 6:24pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/28 "2023-07-14T18:24:35Z")
> [@crazyjoe](#):
>
> Instead, the ass-clowns in the “open” lane use it as an opportunity to shorten their journey by rapidly passing all the cars in the “waiting their turn” lane.
But if we managed to somehow get everyone to do a zipper merge correctly there wouldn’t be an open lane for “ass-clowns” to pass everyone else. People in both lanes would be waiting their turn.
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### Author:  [@Mallard](https://boards.straightdope.com/u/Mallard)
#### Post date: [July 14, 2023, 7:04pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/29 "2023-07-14T19:04:13Z")
> [@Hampshire](#):
>
> Like many northern states we are in the midst of road construction season in Minnesota and of course that comes with the local news outlets obligatory story about how people just can’t seem to get on board with the zipper merging. Even after PSAs aired people still were reluctant to follow step and now traffic cams showing road rage incidents of those not letting other “cut” into the line.
> I see this as more of a failure of the current signage they use. They seem to either be “left lane ends ahead, merge right” or “right land ends ahead, merge left” which is just a mess waiting to happen IMHO. The righteous rule followers will immediately get over as instructed and then start to get peeved as others speed on by.
> Couldn’t this all just be resolved by changing the signage to **“lanes merge ahead, use both lanes”?**
> You wouldn’t have people thinking they were in the “proper” instructed lane and people would be more likely to stay in both down to the zipper point.
Zipper merges in large road construction areas are common here. But people who merged early will sometimes get resentful to those who did not. If used properly, however, zipper merges work well and are the only way to go, IMHO.
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### Author:  [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)
#### Post date: [July 15, 2023, 12:36am UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/30 "2023-07-15T00:36:48Z")
I’m going to say no, at least in the Front Range. I’ve noticed a growing trend in that when a person signals to change lane, cars (usually trucks) that are three lengths behind them in the open lane say, “Fuck you!!! You’re not getting in front of me!!!” and cut them off. Last weekend I had a car behind me change lanes and cut me off when I signaled. It’s not a failure of signage. It’s that people are aholes.
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### Author:  [@Spiderman](https://boards.straightdope.com/u/Spiderman)
#### Post date: [July 15, 2023, 1:12am UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/31 "2023-07-15T01:12:38Z")
> [@ZipperJJ](#):
>
> I don’t have anything to add, I just always feel compelled to post in threads about zippers.
Just button it, bub!
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### Author:  [@Shoeless](https://boards.straightdope.com/u/Shoeless)
#### Post date: [July 15, 2023, 1:55pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/32 "2023-07-15T13:55:45Z")
There’s an intersection near our neighborhood that has kind of a mini zipper merge. Two lanes in each direction, but eastbound traffic merges to one lane immediately after the light. People generally line up in the left lane at the light because they know the right lane isn’t going anywhere. It’s not really a problem because there are rarely more than about two or three cars lined up anyway, but occasionally you have _that one guy_ who gets in the right lane with the intent of jumping ahead of the cars on the left as soon as the light changes.
(Sometimes, as I’m approaching the intersection and a few cars are lined up on the left and the right lane is clear and I can tell the light is about to change, I will stay in the right lane and pass everyone just as the light goes green. Then I wonder whether that was a dick move or not.)
The point being, this intersection was obviously designed for people to merge after the light and yet there is still that “people in the right lane are dicks” stigma.
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### Author:  [@Mangetout](https://boards.straightdope.com/u/Mangetout)
#### Post date: [July 15, 2023, 3:35pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/33 "2023-07-15T15:35:35Z")
That thing (the merge-into lane being slower) is usually a result of too many people merging too early. Volume of traffic in that lane increases, speed decreases, the other lane looks ‘empty’
People who drive down the empty lane to merge at the merge point are doing what they’re supposed to do; it only looks like queue-jumping because everyone else got in the queue too soon.
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### Author:  [@WildaBeast](https://boards.straightdope.com/u/WildaBeast)
#### Post date: [July 15, 2023, 4:33pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/34 "2023-07-15T16:33:15Z")
> [@Shoeless](#):
>
> There’s an intersection near our neighborhood that has kind of a mini zipper merge. Two lanes in each direction, but eastbound traffic merges to one lane immediately after the light. People generally line up in the left lane at the light because they know the right lane isn’t going anywhere. It’s not really a problem because there are rarely more than about two or three cars lined up anyway, but occasionally you have _that one guy_ who gets in the right lane with the intent of jumping ahead of the cars on the left as soon as the light changes.
This is the sort of thing that made me say that Californians seem to be already on board with the zipper merge. There’s an intersection just like that where I live – two lanes merge into one shortly after the light. I used to go through it daily when I had to work from the office. Except unlike people where you are, around here people line up about equally in both lanes, and do a zipper merge after the light. And I always find it extremely satisfying to participate in a perfect zipper merge like that.
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### Author:  [@carrps](https://boards.straightdope.com/u/carrps)
#### Post date: [July 15, 2023, 4:56pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/35 "2023-07-15T16:56:39Z")
> [@WildaBeast](#):
>
> I wonder if there’s a cultural difference between California and Minnesota. In my observation in places where the road narrows from two lanes down to one, people here are totally on board with the zipper merge. Maybe it has something to do with our infamous traffic, which almost necessitates utilizing all the lanes.
I was going to make a similar comment. For the most part, Californians are fine with the zipper merge. A lot of us have almost as much mileage under our belts as long haul truckers. When you spend a lot of time on the road, you want to contribute to making it as painless as possible.
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### Author:  [@DesertDog](https://boards.straightdope.com/u/DesertDog)
#### Post date: [July 15, 2023, 5:06pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/36 "2023-07-15T17:06:18Z")
> [@Gorsnak](#):
>
> I have no idea what the solution is, aside from hammering on the point in driver ed and waiting several decades for driving culture to change.
This is the country where no one has figured out yet how to use a traffic circle. There is no hope.
[Diverging diamond interchanges](https://en.wikipedia.org/wiki/Diverging_diamond_interchange) are now appearing. Good luck with that…
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### Author:  [@Kropotkin](https://boards.straightdope.com/u/Kropotkin)
#### Post date: [July 15, 2023, 5:33pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/37 "2023-07-15T17:33:48Z")
Granted that, as some have noted, people can be a-holes, I think it’s fair to say we have created conditions that create and reinforce a-hole behaviour: crowding, congestion, failure to build proper transportation infrastructure, and more. Instead of thinking of changing human nature, a dubious concept at best,we might take up the undeniably difficult but possible task of changing the conditions that create a-holes. And then those bastards won’t be cutting me off or refusing to let me in at the goddammed zipper point.
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### Author:  [@Horatius](https://boards.straightdope.com/u/Horatius)
#### Post date: [July 15, 2023, 5:39pm UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/38 "2023-07-15T17:39:17Z")
> [@Shoeless](#):
>
> The point being, this intersection was obviously designed for people to merge after the light and yet there is still that “people in the right lane are dicks” stigma.
We have a merge like that at the end of one of our highway off-ramps, and it drives me nuts. People will stick to one lane, even when they’re backing up all the way to the highway, rather than use the “dick’s lane”.
This is particularly bad this year, as several of the offramps just past this one are closed for construction, so this off-ramp is getting probably three times its normal usage. But it’s like pulling teeth to get people to use both lanes.
I console myself with the knowledge that at least I’ll be ahead of most of them after the merge.
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### Author:  [@crazyjoe](https://boards.straightdope.com/u/crazyjoe)
#### Post date: [July 16, 2023, 2:07am UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/39 "2023-07-16T02:07:10Z")
No, see, this is wrong, it is not going slow because too many people got over too early.
I’ve proven this to myself by using my own car to create a choke point ahead of the merge point. Once that is done and all the ass-clowns have merged, traffic moves quickly into the merge lane and flows more smoothly.
It is OK to use the open lane, but zipper merge requires you to match speed and blend with the traffic in the slow lane, not simply pass all the “suckers” sitting in the merge lane.
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### Author:  [@Mangetout](https://boards.straightdope.com/u/Mangetout)
#### Post date: [July 16, 2023, 7:32am UTC](https://boards.straightdope.com/t/is-the-resistance-to-the-zipper-merge-a-failure-of-signage/987005/40 "2023-07-16T07:32:55Z")
post deleted. (personal jab inappropriate for the forum. Sorry)
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