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Washington, Minnesota officially endorse a “safer, faster” traffic merge

arstechnica.com

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Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#71

Post by SoftwareMaven »

john_b wrote: post #59
notacoward wrote: post #27

Zipper merging works great as long as everyone on both sides is willing to alternate (or if strong enforcement requires them to do so). Otherwise, letting "late mergers" scream past fifty "early mergers" often creates a situation worse than simple early merge. There's plenty of blame to go around. * The vast majority of the people blasting down the late-merge lane clearly have no interest in alternating or merging in…

> "Without enforcing proper merge behavior on both sides, zipper merge just becomes a big Prisoners' Dilemma game with a few defectors screwing all of the cooperators." Except unlike prisoner's dilemma, it's not a zero (or negative) sum game. The entire traffic flow can speed up if zipper merging is done. The "late mergers" don't have to risk losing their game of "chicken" while the "vigilantes" don't have to deal wi…

WRT to your footnote, I also can't count the number of times I've seen that person on the side street come into traffic and get t-boned by the car that didn't stop in the next lane over. Letting people cross traffic like that isn't just illegal, it's downright dangerous[1]. As a motorcycle rider, few situations scare me more than seeing a lane of stopped traffic next to a clear lane.

1. The same thing applies to stopping to let people turn left across traffic, where the left lane of oncoming traffic is stopped and the right lane is clear.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#72

Post by nardi »

malandrew wrote: post #35

That video explanation made no sense to me. Basically the "interface" presented to the drivers has not changed, so why would drivers deviate from how they currently merge? Because the government said so? I don't see this working. However there are two solutions that could promote zipper merging: (1) Force both lanes to the center before moving that center lane to the side that is available ahead: ____________________…

Option 1 leads to "no, after you" behavior, steers two cars directly at each other, and probably would be a disaster.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#73

Post by dionidium »

slantyyz wrote: post #62
ericHosick wrote: post #40

Earlier quoted context omitted.

Zipper merging is the optimal solution. People early merge because they think it is the optimal/moral/better/'done my part' solution. If everyone knew about zipper merging there would be no early mergers (and 'late mergers' don't exist within the context of zipper merging).

>> Zipper merging is the optimal solution. People early merge because they think it is the optimal/moral/better/'done my part' solution. It is optimal only when the local driving culture allows it to be. I live in an area where drivers are extremely selfish and the police don't seem to spend a lot of time ticketing bad drivers, so zipper merging typically doesn't work here.

I live in an area where drivers are extremely selfish...so zipper merging typically doesn't work here.

This is backwards. Zipper merging doesn't work when drivers attempt to be unselfish by merging early, which results in vigilante lane blockage of those who weren't as considerate. In other words, I'm not being selfish when I block late mergers; I'm enacting justice on other people who were being selfish.

The system works when all parties recognize that the best thing for everyone is to merge late.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#74

Post by _delirium »

joshwa wrote: post #69
_delirium wrote: post #63

Earlier quoted context omitted.

You could just make two exit lanes in that case, and merge them as or after they exit. People exiting at the last minute from a non-exit lane though aren't really merging, but rather changing lanes. And it doesn't really result in a proper zipper merge since not everyone is exiting, so you can't predictably alternate cars.

I guess I mean that they shouldn't be exit lanes at all, but should be used as extra capacity to facilitate zipper merges. In the case above, the exit lanes stretch back almost 1/2 a mile, which is waaay above the actual demand for that exit, esp in the evening hours.

Oops, I read your case backwards (I'm not familiar with that exit). I thought you meant that there were too many people exiting for the one exit lane, so you were proposing people from the 2nd-to-right lane should be able to zipper-merge into the exit lane right before it exits.

The reverse (merging out of the exit-only lane to stay on the freeway), I think usually works better with a late-merge, but you do still have the problem that you can't do a proper zipper merge, because the lanes aren't fully merging, so you can't alternate one-right/one-left. Instead some cars want to lane-change and some want to continue in the lane, which adds at least a little complexity.

It could be partly improved by signage changes though, it sounds like, to just mark the exit lane later.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#75

Post by ericHosick »

justinpaulson wrote: post #61
ericHosick wrote: post #40

Earlier quoted context omitted.

Zipper merging is the optimal solution. People early merge because they think it is the optimal/moral/better/'done my part' solution. If everyone knew about zipper merging there would be no early mergers (and 'late mergers' don't exist within the context of zipper merging).

Zipper merging is only optimal if traffic is already slowed down dramatically. If traffic is still moving at any kind of speed, then early merge when there is space available will clear congestion faster than everyone driving up to the merge point and hoping that it works out.

> Zipper merging is only optimal if traffic is already slowed down dramatically.

I agree. But note that the idea of Zipper merging is when traffic has already slowed down, not when it is still moving.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#76

Post by peeters »

justinpaulson wrote: post #61
ericHosick wrote: post #40

Earlier quoted context omitted.

Zipper merging is the optimal solution. People early merge because they think it is the optimal/moral/better/'done my part' solution. If everyone knew about zipper merging there would be no early mergers (and 'late mergers' don't exist within the context of zipper merging).

Zipper merging is only optimal if traffic is already slowed down dramatically. If traffic is still moving at any kind of speed, then early merge when there is space available will clear congestion faster than everyone driving up to the merge point and hoping that it works out.

No, it's provably optimal in flowing traffic as well. However, the "merge point" is variable depending on traffic speed.

Obviously when you're going 100 km/h, the ideal merge point is significantly farther back than when it's stop and go. Nobody is saying you should wait until you're 20 feet from the barrier and then swerve into the other lane. But it's not like that's unique to this situation.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#77

Post by nardi »

justinpaulson wrote: post #61
ericHosick wrote: post #40

Earlier quoted context omitted.

Zipper merging is the optimal solution. People early merge because they think it is the optimal/moral/better/'done my part' solution. If everyone knew about zipper merging there would be no early mergers (and 'late mergers' don't exist within the context of zipper merging).

Zipper merging is only optimal if traffic is already slowed down dramatically. If traffic is still moving at any kind of speed, then early merge when there is space available will clear congestion faster than everyone driving up to the merge point and hoping that it works out.

This is the commonly held belief that is false. It is false because traffic is caused by lack of capacity, not inefficient driving.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#78

Post by dionidium »

ics wrote: post #70
john_b wrote: post #59

Earlier quoted context omitted.

> "Without enforcing proper merge behavior on both sides, zipper merge just becomes a big Prisoners' Dilemma game with a few defectors screwing all of the cooperators." Except unlike prisoner's dilemma, it's not a zero (or negative) sum game. The entire traffic flow can speed up if zipper merging is done. The "late mergers" don't have to risk losing their game of "chicken" while the "vigilantes" don't have to deal wi…

> [...] inconveniencing everyone behind them for the self satisfaction of having helped the one person they can see. Or because you know that otherwise they'll be at that crossing for the next hour if nobody's willing to let them by. Perhaps there are some funny allusions to net neutrality to be made here...

Just because you want to turn left, doesn't mean you have to sit helpless waiting to do so. You're allowed to turn right and locate a safe place to turn around.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#79

Post by VikingCoder »

dusing wrote: post #11
ChikkaChiChi wrote: post #4

In practice zipper merging works amazingly well. MNDOT has used signage to tell drivers to maintain speed and stay in their lanes for the past few years of construction in the northern Twin Cities. You wouldn't believe how much faster traffic moves when these simple reminders are posted. The problem is that without the signs (and enforcement) drivers in the Twin Cities Metro regularly shoot to seal any gap that may a…

I live in the Twin Cities and "Minnesota nice" means merging incredibly early when a lane is posted as closed. As a transplant I can always count on getting and extra 1/2 - 1 mile ahead by staying in the closed lane. It is getting better, but still 40% of the time the car at the end of the zipper merge is NOT happy to see you, and thinks they are letting you in. Signage is helping at the big construction areas.

"Getting ahead" means you're not following the whole point of this idea, which is to MINIMIZE the speed differential between the two lanes.

If you want to show people how it's done, you go the same speed as the cars next to you in the open lane, and zipper merge at the end.

GRRRRR.

Yes, THEY are doing it wrong, because they're early merging. (IDIOTS!) But you are ALSO doing it wrong.

I'm reminded of the George Carlin comment that everyone who drives slower than you is an idiot, and everyone who drives faster than you is an asshole.

Re: Washington, Minnesota officially endorse a “safer, faster” traffic merge

#80

Post by ericHosick »

Klinky wrote: post #51
ericHosick wrote: post #40

Earlier quoted context omitted.

Zipper merging is the optimal solution. People early merge because they think it is the optimal/moral/better/'done my part' solution. If everyone knew about zipper merging there would be no early mergers (and 'late mergers' don't exist within the context of zipper merging).

In simulations zipper merging is an optimal solution. In reality, relying on thousands of drivers to properly follow specific directions and be completely aware of their surroundings is a flawed solution. Telling people how to do something efficiently doesn't mean they'll do it that way. People are extremely loose when it comes to following driving rules, e.g. speed, texting, minimum distances, merging, etc..

I agree that telling anyone to do anything doesn't mean they will do it (change their habits).

However, educating people does allow them to make better decisions.

Rules themselves aren't always the best/optimal/safest solution either and being loose may be the best solution.

For example, in one country in Asia if you are "in-front" of someone you have the right to merge/enter a roadway/get on a free way/change lanes over the person already in the lane. This is just cultural and is so much better than what we have in the west (like the USA). If someone changes lanes and "hits you", it is your fault (unless you were in-front of them).

Makes it so much easier to get on the free way, change lanes, etc. as you only have to worry about what is in front of you. Not what is in front of you, behind you, next to you, etc. There are no "blind spots" etc.

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