Zipper Merge News

[Amtrakprod]

NCDOT used this sign


iPhone

[Revive 755]

^ So I am supposed to watch for a giant zipper?

[DaBigE]

NCDOT used this sign


iPhone

Two rail lines crash together in a tunnel ahead?

[jakeroot]

I think the sign makes sense, though I'd like a supplementary "TAKE TURNS MERGING" tab below it.

[signalman]

I think the sign makes sense, though I'd like a supplementary "TAKE TURNS MERGING" tab below it.

Agree.  I'd guess the general motoring public will not make sense of that sign.  I can't recall ever hearing zipper merging being referred to as such in common verbiage.

[NoGoodNamesAvailable]

NYSDOT just uses an advance "single lane" sign and a modified symmetrical W4-2 sign with no dotted line. It seems to get the idea across fine, notwithstanding the one car out of every 20 or so who'll cut the line for no reason other than feeling more entitled to it.

[jakeroot]

I think the sign makes sense, though I'd like a supplementary "TAKE TURNS MERGING" tab below it.

Agree.  I'd guess the general motoring public will not make sense of that sign.  I can't recall ever hearing zipper merging being referred to as such in common verbiage.

I guess it depends on your location. WSDOT uses the "zipper" terminology in their PR (not on actual signs) often enough for it to have entered the public lexicon in Seattle. But areas less prone to congestion may not use or have heard of the term.

[thenetwork]

NCDOT used this sign


iPhone

Two rail lines crash together in a tunnel ahead?

If right after a Rest Area:  Did You Zip Up?? (albeit the sign in the photo would then be considered upside-down).

[MNHighwayMan]

I think the sign makes sense, though I'd like a supplementary "TAKE TURNS MERGING" tab below it.

MnDOT even has such a sign (though phrased as "TAKE TURNS AT MERGE.")



Edit to add: A similar sign was also posted at the merge point.



(I'm also now regretting getting more pictures of other similar signs in other I-35 work zones. There's been a lot of them the last couple years, so hopefully they should be mostly done with for a while. )

[kphoger]

I think the sign makes sense, though I'd like a supplementary "TAKE TURNS MERGING" tab below it.

Agree.  I'd guess the general motoring public will not make sense of that sign.  I can't recall ever hearing zipper merging being referred to as such in common verbiage.

I guess it depends on your location. WSDOT uses the "zipper" terminology in their PR (not on actual signs) often enough for it to have entered the public lexicon in Seattle. But areas less prone to congestion may not use or have heard of the term.

I have my doubts that, even in an area where the term "zipper merge" is used extensively in PR, it would be readily understood by the majority of drivers.  In other words, take 1000 drivers and ask them what a zipper merge is, and I'd bet at least half of them wouldn't know.  But even if they do, it's still a crappy warning sign because it's just a picture of a zipper.  It doesn't say anything about a merge (just a zipper, and it's quite the cognitive leap to go from "watch out for the huge zipper" to "lanes merging ahead"), plus it doesn't actually tell you what to do (it's just telling you to watch out).

tl;dr - It's cute but worthless.

[kphoger]

(I'm also now regretting getting more pictures of other similar signs in other I-35 work zones. There's been a lot of them the last couple years, so hopefully they should be mostly done with for a while. )

I'm sure you've been sitting in 5-mph traffic during those construction projects enough times to have snapped some pictures, too!  I swear, Owatonna was a four-letter word for a while.

[jakeroot]

I think the sign makes sense, though I'd like a supplementary "TAKE TURNS MERGING" tab below it.

Agree.  I'd guess the general motoring public will not make sense of that sign.  I can't recall ever hearing zipper merging being referred to as such in common verbiage.

I guess it depends on your location. WSDOT uses the "zipper" terminology in their PR (not on actual signs) often enough for it to have entered the public lexicon in Seattle. But areas less prone to congestion may not use or have heard of the term.

I have my doubts that, even in an area where the term "zipper merge" is used extensively in PR, it would be readily understood by the majority of drivers.  In other words, take 1000 drivers and ask them what a zipper merge is, and I'd bet at least half of them wouldn't know.  But even if they do, it's still a crappy warning sign because it's just a picture of a zipper.  It doesn't say anything about a merge (just a zipper, and it's quite the cognitive leap to go from "watch out for the huge zipper" to "lanes merging ahead"), plus it doesn't actually tell you what to do (it's just telling you to watch out).

tl;dr - It's cute but worthless.

I guess it depends on whether or not the person experiences a merge on their commute. If they do, they're probably familiar with the concept. If not, I doubt they've bothered to listen to any PR to begin with.

Regardless, I'd hate to see any new warning signs added to the MUTCD without symbols. As implemented, I wouldn't say NC's sign is worthless (I'm sure drivers familiar with the "zipper" got the connection), but (as I suggested before) a supplemental tab would massively improve recognition of the expected behavior.

I saw something like this on another website, and I think it gets the point across. I've recreated the sign and added the text.

[MNHighwayMan]

(I'm also now regretting getting more pictures of other similar signs in other I-35 work zones. There's been a lot of them the last couple years, so hopefully they should be mostly done with for a while. )

I'm sure you've been sitting in 5-mph traffic during those construction projects enough times to have snapped some pictures, too!  I swear, Owatonna was a four-letter word for a while.

That Owatonna closure was definitely fun, for sure. Unfortunately it took me this thread to realize that Minnesota's signage is certainly not the norm, and actually probably pretty far above other states in terms of quality. Where else would they use flashing beacons ten miles in advance of a lane closure to warn of potential backups?

[DaBigE]

I saw something like this on another website, and I think it gets the point across. I've recreated the sign and added the text.

I like this a whole lot better. IMO, the tab at the top could easily be omitted, as it just sucks up reading/comprehension time.

[jeffandnicole]

I guess it depends on whether or not the person experiences a merge on their commute. If they do, they're probably familiar with the concept. If not, I doubt they've bothered to listen to any PR to begin with.

Yep.  I see this on a fairly regular basis over here.  On our NJ Route 55, which is both a commuter highway and shore route, on weekdays you see people staying in both lanes up to the very end.  On weekends, when you get the Pennsy driver coming back from their vacation who probably doesn't commute very often, they merge over very early, and in some situations feel they should ride the center line because they feel that the merging should've happened when they did it. 

The weekday commuting merging goes much more smoothly than the weekend tourist merging.

[kphoger]

I saw something like this on another website, and I think it gets the point across. I've recreated the sign and added the text.

I like this a whole lot better. IMO, the tab at the top could easily be omitted, as it just sucks up reading/comprehension time.

Agreed.  The sign with bottom plaque is all that's needed.  "Zipper" is just a cute PR name that drivers don't actually need to know.

[empirestate]

I have my doubts that, even in an area where the term "zipper merge" is used extensively in PR, it would be readily understood by the majority of drivers.  In other words, take 1000 drivers and ask them what a zipper merge is, and I'd bet at least half of them wouldn't know.  But even if they do, it's still a crappy warning sign because it's just a picture of a zipper.  It doesn't say anything about a merge (just a zipper, and it's quite the cognitive leap to go from "watch out for the huge zipper" to "lanes merging ahead"), plus it doesn't actually tell you what to do (it's just telling you to watch out).

I think that's a fair doubt. After all, how many people still don't know how a roundabout works, despite extensive PR from a number of different state DOTs for like 25 years now?

That said, I'm guessing the zipper sign isn't a standalone install, but part of a broader signage scheme; there are probably other signs nearby that contextualize what it means.

On our NJ Route 55, which is both a commuter highway and shore route, on weekdays you see people staying in both lanes up to the very end.  On weekends, when you get the Pennsy driver coming back from their vacation who probably doesn't commute very often, they merge over very early, and in some situations feel they should ride the center line because they feel that the merging should've happened when they did it.

Which is interesting (and to the same point as my first quote), since Pennsy is one state that routinely instructs drivers to zipper-merge. ("Use both lanes to merge point" is their verbiage.)

[bzakharin]

You don't have to know anything about roundabouts to follow the yield signs. Those are long established and in use nationwide for various reasons. The zipper signs are non-standard, and has no nationwide standard.

[1995hoo]

.... they merge over very early, and in some situations feel they should ride the center line because they feel that the merging should've happened when they did it. 

....

I see that sort of thing pretty much anywhere a merge occurs, and it doesn't matter whether it's commuters or long-distance traffic. Saw it in Indiana despite a sign saying to go to the end and take turns–instead, most people panicked and rushed to form a single line a mile or two in advance. (Of course we have one person in this thread who thinks that's how it's supposed to be.) I still cannot fathom how some people cannot understand that it makes no sense whatsoever if every different driver designates his own merge point and says nobody else can merge after that spot.

It's really maddening when one of the lanes is configured so that it can either merge or exit yet people try to block anyone using it. The ramp from the Ninth Street Tunnel to southbound I-395 in DC was like that for years–one lane exits to the right from the tunnel, and another lane to the right of that one comes down from D Street SW to join the ramp. For years, it was striped as two lanes, and partway down the ramp the right lane allowed you either to exit to the right to Maine Avenue or to go straight and merge with the left lane into a single lane onto I-395. Despite the clear two-lane configuration with what should have been a zipper merge at the end, some people were convinced anyone who was coming from D Street and who didn't stop right at the beginning to get over was somehow "cutting," and the people who felt that way would try to straddle both lanes, even though the right lane gave the option of exiting to the right onto Maine Avenue (I often exit that way, and there's no reason why I should be stuck behind the "merge-early-block-everyone-else" crowd when I'm exiting that way). The ramp is no longer striped as two lanes, so now it's a bit of a crapshoot from one day to the next how the traffic will form up (long-time ramp users who are polite try to form two lanes to allow people headed to Maine Avenue to get past).

[kalvado]

(Of course we have one person in this thread who thinks that's how it's supposed to be.)

Actually I got a thought regarding all this...
Is there any correlation between zipper approach altitude and home area?
Apparently, queue length and possibility of blocking previous exits is the only valid reason to enforce zipper. For such concern to be valid, the length of routine backup has to be comparable with distance between exits - e.g. heavy traffic and dense exits. Which mostly means megapolis environment.
As far as I understand, you live in a core DC area, which certainly qualifies you for "megapolis"... @jeffandnicole is another megapolis datapoint.
On the other hand, I can think of at least to people who are from lighter traffic area and have pretty sceptic oppinion about zipper. So is that a correlation?

[empirestate]

You don't have to know anything about roundabouts to follow the yield signs. Those are long established and in use nationwide for various reasons. The zipper signs are non-standard, and has no nationwide standard.

Exactly. So if people still don't understand roundabouts, despite them being very standard by now, it's very fair to doubt that they'll understand the zipper sign, despite any aggressive PR that may be accompanying them.

[NoGoodNamesAvailable]

I think the sign makes sense, though I'd like a supplementary "TAKE TURNS MERGING" tab below it.

Agree.  I'd guess the general motoring public will not make sense of that sign.  I can't recall ever hearing zipper merging being referred to as such in common verbiage.

I guess it depends on your location. WSDOT uses the "zipper" terminology in their PR (not on actual signs) often enough for it to have entered the public lexicon in Seattle. But areas less prone to congestion may not use or have heard of the term.

I have my doubts that, even in an area where the term "zipper merge" is used extensively in PR, it would be readily understood by the majority of drivers.  In other words, take 1000 drivers and ask them what a zipper merge is, and I'd bet at least half of them wouldn't know.  But even if they do, it's still a crappy warning sign because it's just a picture of a zipper.  It doesn't say anything about a merge (just a zipper, and it's quite the cognitive leap to go from "watch out for the huge zipper" to "lanes merging ahead"), plus it doesn't actually tell you what to do (it's just telling you to watch out).

tl;dr - It's cute but worthless.

I guess it depends on whether or not the person experiences a merge on their commute. If they do, they're probably familiar with the concept. If not, I doubt they've bothered to listen to any PR to begin with.

Regardless, I'd hate to see any new warning signs added to the MUTCD without symbols. As implemented, I wouldn't say NC's sign is worthless (I'm sure drivers familiar with the "zipper" got the connection), but (as I suggested before) a supplemental tab would massively improve recognition of the expected behavior.

I saw something like this on another website, and I think it gets the point across. I've recreated the sign and added the text.

PANYNJ uses a nearly identical sign. In downstate NY alternate merging is pretty socially engrained  so people tend to do it in appropriate situations whether or not there's signage.

[jakeroot]

I saw something like this on another website, and I think it gets the point across. I've recreated the sign and added the text.

I like this a whole lot better. IMO, the tab at the top could easily be omitted, as it just sucks up reading/comprehension time.

Agreed.  The sign with bottom plaque is all that's needed.  "Zipper" is just a cute PR name that drivers don't actually need to know.

Ideally, I'd rather not have any additional text. The text on the bottom is arguably much more important.

I included the term "zipper merge" on top since that would be the text equivalent. "Take turns merging" is more of a regulatory message, whereas "zipper merge" is a warning of the situation, alongside established terms like "right lane ends". I'm not sure what other term might be better, but "zipper merge" is (as I said before) decently well-established in some places.

[DaBigE]

I saw something like this on another website, and I think it gets the point across. I've recreated the sign and added the text.

I like this a whole lot better. IMO, the tab at the top could easily be omitted, as it just sucks up reading/comprehension time.

Agreed.  The sign with bottom plaque is all that's needed.  "Zipper" is just a cute PR name that drivers don't actually need to know.

Ideally, I'd rather not have any additional text. The text on the bottom is arguably much more important.

I included the term "zipper merge" on top since that would be the text equivalent. "Take turns merging" is more of a regulatory message, whereas "zipper merge" is a warning of the situation, alongside established terms like "right lane ends". I'm not sure what other term might be better, but "zipper merge" is (as I said before) decently well-established in some places.

Given your explanation, the "Zipper Merge" plaque, if used, should go below the symbolic sign, as it's a supplementary plaque (similar to plaques used for the Circular Intersection sign or Divided Highway Begins/Ends). Placing it on top detracts from the more important information. The only plaques that should go on top of installations like this would be ones like New or Notice, as they're meant to draw attention/enhance conspicuity of the main sign.

I have a similar grip with municipalities that insist on installing a Roundabout plaque above a regulatory lane designation sign. What makes my example even worse, is how small the text is in relation to its location relative to the approach and how many bits of information there are for the driver to have to process. My example has something else radically wrong with it...kudos to whomever finds what I am referring to.

[1995hoo]

^^

There appears to be a stop sign on that signpost to the right, directed at the short sidewalk piece that meets the road. What's that for?