I've been seeing a lot of attention to the fabled zipper merge lately and I gotta say: I don't like it, and it doesn't appear to work.
I get the concept, and if we lived in perfect, it might possibly work. But here in realityville one lane of traffic is already as necked down as it gets and should flow at whatever speed they can handle through the congestion. Asking everyone to politely ease their cars together doesn't berkeleying work.
It's like going to the amusement park and waiting in line for the new supercoaster. Supercoaster can process 800 people per hour. Having two lines come up to it from different ends doesn't make it faster to get on the ride, it just makes each line slower. And when everyone is already merged (yay, good job team) someone zipping up to the head of the line is like the douchey kid who's dad paid double for the "fast pass". Might be faster for you I suppose but not for those of us in line. Remember, supercoaster can only take 800 an hour, douchey kid just made me wait a little longer.
TLDR: berkeley the zipper.
aaaaand fight!
What the zipper does is reduce the amount of road that gets backed up when there's congestion. It's important not to let that go so far backwards that it overflows the previous intersection or you just get all kinds of cascading effects. For a SuperCoaster 3000 you can have a single line that snakes back and forth, but that's not really practical for cars.
That's fine. You can sit in traffic and I'll be the shiny happy person that uses the open lane till the end.
I don't like sitting in traffic
Just, one request. Don't block the open lane thinking you are helping the situation.
GRTechGuy said:
"Just, one request. Don't block the open lane thinking you are helping the situation"
I do, and it does. I've seen it play out over and over again.
I've lost this debate before, but I stand on my perspective.
It. Doesn't. Work.
It's one of those theory vs reality debates. In theory, it works great. Reality? Heck no.
It depends on how heavy the traffic is, how far back the signs start, and how many people buy in to the system. Heavy flow, and a 1-1-1-1 system with people all going when they should, it works great until some douche stops way too far back to be polite.
Light traffic, everyone should be lined up well before they have to, so you don't have to wait for some douche to work up the courage to merge.
As always, there is no right answer for all cases.
I'll zipper if that appears to be the norm for that particular road. I will however, force your ass into the curb/median/barrels if try to squeeze in after I yield to someone merging/they yield to me. One at a time, jerkweed.
This upsets my deeply engrained sense of fairplay.
To the people who wait till the last second. I'm sorry for running you off the road. My work truck and my $200 car will win that fight every time.
mtn
MegaDork
10/6/21 6:58 p.m.
Professor_Brap (Forum Supporter) said:
To the people who wait till the last second. I'm sorry for running you off the road. My work truck and my $200 car will win that fight every time.
They're following the rules though...
Ill take the open option and zipper when I can towards the front. That's what it was designed for. I've never seen that open lane used except by us "shiny happy people", so I have no idea if it works or not, but I'll take that free time no problem.
Driven5
UltraDork
10/6/21 7:28 p.m.
The reason it doesn't work, and never will, is that too many of both it's proponents AND it's detractors are doing their part of it wrong.
In reply to mtn :
I'm mostly talking about the people who wait till the last possible second and then want you to slow down to let them in.
For those saying it doesn't work, what's the fix?
This sounds like the mayor of Minneapolis who won his campaign by saying he would rid the city of the highway onramp throttling lights.
Yeah, he wrecked EVERYONES commute for a few months until they put them back.
It's hard to see the macro effects on traffic from the individual perspective of driver.
My understanding is that traffic studies have shown that using all available lanes until the merge is the most effective plan (for everyone) in most cases. Dunno if that means "zipper" or not.
Steve_Jones said:
For those saying it doesn't work, what's the fix?
You don't have to propose a fix in order to yell at the clouds!
There is no good way to close a lane, and if everyone could participate in society like an adult it would work as well as anything else. Unfortunately we've proven time and again that this is asking too much of our fellow Americans.
these have been popping up lately in place of on ramps. Weird at first, but it's growing on me
mtn
MegaDork
10/6/21 8:54 p.m.
RevRico said:
these have been popping up lately in place of on ramps. Weird at first, but it's growing on me
This solved a pretty terrible congestion problem near me. People were up in arms about it, but it works very well.
Steve_Jones said:
For those saying it doesn't work, what's the fix?
V plow.
It's not the zipper effect that riles me up, its someone trying to bully their way in beyond the left side-right side-left side-right side pacing. They berk up the rythm.
mtn said:
RevRico said:
these have been popping up lately in place of on ramps. Weird at first, but it's growing on me
This solved a pretty terrible congestion problem near me. People were up in arms about it, but it works very well.
We have one of these, though it only has the left 2 ramps(relative to the pic). In our situation I don't see where it's much benefit - rather than stopping at the light for people making left turns on/off the ramps, your just stopping for people going straight instead. From what I see of the traffic flow, the majority of cars entering the ramp are coming from the top of the pic, and the ones exiting are mostly heading towards the bottom.
The advocates of this always say the same thing... "As long as nobody's a douche..."
How's that working out?
I read a couple papers on zipper merging a few years ago. One of the "pro" zipper papers conceded that in many situations zipper merging slowed the flow of traffic down, but it was worth it as the lower speed differential between the lanes resulted in fewer serious accidents vs. the one lane at a near standstill and another lane full of shiny happy people barreling down at full speed towards the merge point.
The worst is when traffic is light and a single lane can easily support the traffic volume. All it takes is a few fools who wait until the last minute or can't/won't match the speed of the lane they're merging into to really slow things down or create a dangerous situation.
SVreX (Forum Supporter) said:
The advocates of this always say the same thing... "As long as nobody's a douche..."
How's that working out?
Ok, so what's the fix? Blocking the lane you're not in is a douche move considering the guy you're blocking is doing it correctly. Is that the fix? Be a douche too?
Anecdotal input. One of my best friends in L.A. was a traffic reporter for a radio station, so we spent a fair amount of time in a chopper over the worst traffic in the states. Watching traffic from 1200 feet in L.A. is a complete revelation.
Zippers
only
work
if
you
use
all
lanes
to
the
merge
point.
Full stop.
If everyone gets in the other lane as soon as they see the "this lane ends" sign, it's pretty much a sure-fire accident for someone a mile behind you about 20% of the time. There are even signs in many states that say "use both lanes to merge point" and you always get that vigilante trucker who blocks the closing lane. They have just spent the last 250 miles losing their momentum on hills because of hapless Toyotas messing with their flow, so by-god-dangit, they won't let those pesky 4-wheelers take one more spot ahead of them. Truck drivers are the hall monitors of the road. They can't get a date, so they seek power. I'm a CDL driver and I approve this message.
It should always be treated like a "this lane ends" sign. Just keep moving with traffic, take your turn. The whole idea that you need to instantly comply with a sign warning you about something 2 miles ahead and block people who are doing the right thing causes road rage, accidents, and bullE36 M3tery that doesn't need to happen. In fact, in my state, you MUST use both lanes to the merge point if there is a sign that indicates it. It's the law.
Here's the deal. When everyone merges into a lane early, it causes stops, slow-downs, and death. Think about when we see a disabled vehicle, or a cop with a customer on the side of the highway, we scoot over a lane, right? It doesn't cause a 3-mile backup. At best you have to slow down a couple MPH. construction is a whole new level for most drivers and they lose their minds. Will there be backups? Yes. Does it have to be an episode of Survivor? No.
Steve_Jones said:
For those saying it doesn't work, what's the fix?
Plain and simple: Education.
In the US, you have to show that you can parallel park, observe the speed limit, and use a turn signal during a 600-foot course before someone signs off on your license, and it costs minimal dollars. We like to say that "driving is a privilege, not a right," but if you can demonstrate that you know the difference between a brake pedal and a steering wheel, you get a license. It's as close to a right as you can get. If you cause an accident, your insurance rates might go up a few dollars. In Germany, you have to take a 45-hour intensive course with a professional driver, the course and license cost about $2000, and if you cause an accident, the police can seize your license and car on the spot. Much higher motivation to understand traffic dynamics. This is why the Autobahn is one of the safest highways in the world while the 405 in L.A. is one of the deadliest. Our requirements for driver licensing are a joke.
SVreX (Forum Supporter) said:
The advocates of this always say the same thing... "As long as nobody's a douche..."
How's that working out?
To be fair that statement works for everything including traffic.
