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June 23, 2014 7:01 AM   Subscribe

Want to get out alive? Follow the ants - "Emergency exits work better when they are obstructed."

Crush Point: When large crowds assemble, is there a way to keep them safe?
posted by the man of twists and turns (42 comments total) 27 users marked this as a favorite

 
Nice work on the title.
posted by codacorolla at 7:21 AM on June 23 [14 favorites]


The 2nd link is from 2011 and talks about the importance of the (at the time) pending ruling on OSHA's citation of Wal-Mart for Jdimytai Damour's death. The original judge ruled against Wal-Mart but as of last fall they were still appealing the $7000 fine.
posted by ghharr at 7:24 AM on June 23 [1 favorite]


WARNING: The second link has the picture of people being crushed against the wire fence at Hillsborough at the very top of the page. I could have done without that, personally, thanks New Yorker.
posted by BeerFilter at 7:27 AM on June 23 [6 favorites]


Shiwakoti and his team are experimenting with placing barriers in front of the Melbourne football stadium exits that lead to the train station.

Urg. Something about this reminds me of the idea to tear down the slums and build glorious designer high-rises for the poor. (Well intentioned, seemed like a good idea, but bad results) I would think when lives are at stake they'd do human testing instead of jumping right from ant model to finished product.
posted by bleep at 7:28 AM on June 23 [2 favorites]


Beginning at midnight, the store began distributing tickets for the steeply discounted electronic items, and by three-fifteen they had all been given out. People arriving when I did weren’t happy. “You said the sale starts at five. That’s false advertising,” one irate customer said to a manager. “It’s not me, it’s them,” the manager said, gesturing toward the ceiling. People were lining up anyway for the ordinary sale-priced items, but there was no joy of the hunt in the line. It was just a line.

Better irate than dead. Whilst YMMV, I've never understood the desire to queue for hours for an item that will be on sale again in 6 months anyway.
posted by arcticseal at 7:38 AM on June 23 [2 favorites]


The local paper just published a story about this yesterday; my city has the world's largest music festival attended by over 800,000 people (starts this wednesday!). Last year they let over 5000 people in without tickets or security patdowns to avoid a crush.

I haven't been to it in years; I'm 5 feet tall and less than 100 lbs and I can't see anything anyway. I get elbowed and shoved and people spill beer on me. And that's just normal crowds; I'm terrified of a real crush.
posted by desjardins at 7:49 AM on June 23 [2 favorites]


Whilst YMMV, I've never understood the desire to queue for hours for an item that will be on sale again in 6 months anyway.

That says a lot more about your economic position than your philosophical or moral position, for what it's worth.
posted by mhoye at 7:54 AM on June 23 [10 favorites]


I remember reading something like this after the Great White concert disaster. The counterintuitive gist was that smaller exits are more efficient. Even though more people could fit through a larger exit the way people react makes them less efficient.

I'm glad we're learning but it's at a horrible expense.
posted by vapidave at 7:57 AM on June 23 [1 favorite]


This is great research; thanks for posting it.
posted by seyirci at 8:01 AM on June 23 [3 favorites]


Thanks ants. Thants.
posted by bicyclefish at 8:06 AM on June 23 [30 favorites]


That says a lot more about your economic position than your philosophical or moral position, for what it's worth.

I'm not a Black Friday kind of shopper (ugh crowds), but my impression is that a lot of people are doing it recreationally (plus normal human avarice, of course), rather than out of pure economic need.
posted by Dip Flash at 8:07 AM on June 23 [7 favorites]


Very interesting research, and it makes intuitive sense -- breaking up the stream of people should result in a slower "release" of people into the choke point of the door, but it does this by creating other choke points and maybe dead zones that could trap people who can't force themselves into the flow past the obstruction (pillar or wall). Ants, I am pretty sure, do better climbing on each other than humans do....

Also, I am pretty sure that the problem fleeing the Hippodrome during the Nika Riots had more to do with the troops assembled to kill the rioters than poor civil engineering. But there were a couple of hilarious incidents at the Hippodrome during those riots, so I may be thinking of the wrong one.
posted by GenjiandProust at 8:14 AM on June 23


That says a lot more about your economic position than your philosophical or moral position, for what it's worth.

Only if you're queuing for basic necessities rather than for luxury goods. Don’t get me wrong, I hate the ‘poor people don’t deserve nice things’ refrain as much as the next socialist, but I do think that we need to be honest about things that are luxuries, which are nice, and everyone deserves once in a while, but no one has a right to.
posted by Ned G at 8:21 AM on June 23 [2 favorites]


I would think when lives are at stake they'd do human testing instead of jumping right from ant model to finished product.

One has to wonder whether this same exit blocking technique is used for sky boxes or only for the rest of us. If it's such a wonderful idea, it would be.
posted by Stoatfarm at 8:21 AM on June 23


One has to wonder whether this same exit blocking technique is used for sky boxes or only for the rest of us. If it's such a wonderful idea, it would be.

Wait, why wouldn't it be? Are you implying that designing exits this way is actually a plan to cause poor people to trample each other?

Economic inequality takes many vicious and subtle forms and I'm never going to defend the people who perpetuate it, but that sounds like a completely over the top conspiracy theory to advance with no evidence.
posted by my favorite orange at 8:30 AM on June 23 [3 favorites]


a lot of people are doing it recreationally

That's pretty much it, along with the poverty of their mass-produced, aspirational consumer products.
posted by jsavimbi at 8:33 AM on June 23


Urg. Something about this reminds me of the idea to tear down the slums and build glorious designer high-rises for the poor.

You'd think it's a bad idea, but it's not. The problem with an exit on a flat wall is people can come at it from any direction, and they have to sort that out to go out the door. A large barricade basically makes everyone *from a distance* divide into two streams.

Interlacing two streams is easy -- left, right, left, right -- and it's been proven time and time again that that barrier, properly designed, lets people get out faster.

The trick -- it has to be properly designed. The key feature is that people need to see it from a distance, so, in the larger room space, they can move to one side or the other. It also needs to be tall and sturdy. A low barrier is a disaster in waiting -- people at a distance don't see it, they push directly to the exit, end up pushing people over the barrier, who then plug the exit and you're now dealing with a trampling disaster. A weak barrier collapses and blocks the exit. Finally, people need to know the exit is behind, but that's actually not the hard part. People who came in that way know, they tend to go back the way they came, and when you get a few people moving purposefully, the rest of the crowd tends to follow them.

I would think when lives are at stake they'd do human testing instead of jumping right from ant model to finished product.

Oops, that was wrong. Sorry 15 people I just killed, but hey, we got valuable data!

And if you RTFA, you would discover they did do human testing as well. The ants led them to both the idea that people tended to follow leaders and that a block in front of the exit actually increased the exit rate, as opposed to the seemingly logical reduction. Testing was then done, in controlled conditions, to see if humans in crowds exhibited similar behavior -- following leaders and moving faster through exits with barriers. The answer was yes. They also learned what's different -- there's no way for people at one side of a crowd to communicate issues to the other side, whereas ants can do so via pheromones.
posted by eriko at 8:35 AM on June 23 [14 favorites]


I remember reading something (maybe here?) that talked about how one area where people are working to develop more realistic human AI is for testing emergency escape routes like this, where animal testing doesn't really work, and human testing isn't ethical. There was a video of someone running a fire simulation where the human actors could be tweaked to be more selfish, more panicked, less rational, etc.
posted by codacorolla at 8:44 AM on June 23 [3 favorites]


Actually, I did "read the fucking article" and the one that cites Shiwakoti merrily plopping barriers in front of the Melbourne stadium exits doesn't mention anything in between the ants and the stadium. I was certainly hoping that a whole goddamn lot of testing happened in between, but the article itself chirpily promotes the idea that s'cool, we can just try these things out because the ants said so.
posted by tavella at 8:46 AM on June 23 [1 favorite]


Movie theatre entrances are kinda built this way, a centre obstacle with aisles to the left and right of the theatre. When you enter you have to chose to turn left or right.

I've been consciously choosing left for years, anecdotally noting that many people turn right. I'm not 100% certain it works, but we do seem to get decent seats.
posted by bonehead at 8:51 AM on June 23 [1 favorite]


This article just shows the oppressive nature of doors.
posted by blue_beetle at 8:55 AM on June 23 [1 favorite]


My big question is whether they've done the signage in such a way that placing a column directly in front of an emergency exit, doesn't make the location of the exit less obvious to a casual passer-by.
posted by TwoWordReview at 9:15 AM on June 23 [1 favorite]


Jeebus. Nautilus is a smart publication, so I figured the comments might be as well.

Just goes to show the wisdom of our hosts' decision to place a $5 obstruction in front of the entrance.
posted by notyou at 9:24 AM on June 23 [6 favorites]


One has to wonder whether this same exit blocking technique is used for sky boxes or only for the rest of us.

Sky boxes get chutes to a padded landing area.
posted by mantecol at 9:41 AM on June 23 [1 favorite]


I really enjoyed both of these articles. It's interesting that crowd-crush disasters have been so much more of a problem when people are moving toward things they want (sale items, concerts, etc.) rather than trying to escape from things like a building fire. Panic is certainly a real thing, but I think people actually manage to be nicer to each other when they know the consequences for the other guy are "might not make it out alive" vs. "might not get the black Friday special that we both want." It's easier to take a zero-sum attitude to the latter situation, that it's either him or me who's going to get that deal, whereas the fire situation can still inspire a hope that both people could make it out and survive.
posted by vytae at 9:44 AM on June 23 [4 favorites]


mhoye: Whilst YMMV, I've never understood the desire to queue for hours for an item that will be on sale again in 6 months anyway.

That says a lot more about your economic position than your philosophical or moral position, for what it's worth.


That you can fantasize that waiting in lines on Black Friday is a poverty indicator says a lot about your nationality, and advertising consumption.
posted by IAmBroom at 9:56 AM on June 23 [9 favorites]


The trick -- it has to be properly designed. The key feature is that people need to see it from a distance, so, in the larger room space, they can move to one side or the other.

The person who wrote this has obviously never tried to enter the Lincoln tunnel at rush hour. :-)
posted by smidgen at 10:32 AM on June 23 [1 favorite]


There's been a lot of research on traffic jams, which operate on a similar shock wave principle. One driver who speeds up, slows down or who won't let someone in front of him causes an immense ripple effect called a phantom traffic jam or jamiton.
posted by desjardins at 10:42 AM on June 23 [1 favorite]


It's interesting that crowd-crush disasters have been so much more of a problem when people are moving toward things they want (sale items, concerts, etc.) rather than trying to escape from things like a building fire.

I'm not sure that's true. The article does focus on it but that's precisely because people usually focus on the opposite and they wanted to point out the counter-intuitive nature. But crowd crush disasters have been a problem for people trying to escape things for literally thousands of years.
posted by Justinian at 11:13 AM on June 23 [1 favorite]


Please nobody talk about the Nike hippodrome disaster. It's too soon.
posted by Justinian at 11:21 AM on June 23 [3 favorites]


Ants, I am pretty sure, do better climbing on each other than humans do....

Challenge accepted.
posted by Fizz at 11:32 AM on June 23 [1 favorite]


[probably best to stick to the topic about crowd crushing and less about poverty/luxury goods/the poor derail]
posted by mathowie at 11:34 AM on June 23


I refuse to believe that jamiton is a real word.
posted by maryr at 11:45 AM on June 23


Mefi posts from 2003 (1, 2) on the Great White nightclub fire with links to similar topics (warning: tasteless jokes in first link)

I'm 99% sure there was a more recent post with a great longform article but I can't find it quickly. I'm fascinated by this stuff for some strange reason.

Mefi posts on the Hillsborough disaster - 1, 2, 3

In case you need a chaser - How to disperse a crowd of kittens
posted by desjardins at 11:55 AM on June 23 [1 favorite]


Movie theatre entrances are kinda built this way, a centre obstacle with aisles to the left and right of the theatre. When you enter you have to chose to turn left or right.

I thought this was more to prevent light from the lobby shining down the aisle and disrupting the projection.
posted by JoeZydeco at 11:58 AM on June 23


Found a few more mefi posts on the topic:

Boston's Cocoanut Grove fire

Love Parade tragedy

Hajj stampede

Tigris River bridge stampede

-------

Chasers: Dolphin "stampede" of 2013. Dolphin stampede of 2008. Slow-motion kittens.
posted by desjardins at 12:09 PM on June 23


Paul Wertheimer sounds like a really interesting guy.
posted by vibratory manner of working at 1:27 PM on June 23 [2 favorites]


Casey Chroust, an executive vice-president of the Retail Industry Leaders Association, told me, “The impact of this case is potentially huge. Does it mean I have to hire an event-management staff next time I hold a doorbuster sale? Does this mean every time you have a hot product—a video game, a Harry Potter book, an iPhone—much less a Black Friday sale, you’ll be liable for potential action if you don’t hire crowd management?”
Oh how I hate the "You're telling me I can't do this shitty thing so I suppose next thing you know I can't do anything" argument. If you're having a sale that has bloody "doorbuster" right there in your own description of it then yes, yes you should be made to event manage that in case people die, ffs. God forbid it should cost you some dollars.

Dying by having the air literally squeezed from your lungs by other panicked people being pressed into you on all sides while you're totally helpless...what a terrifying way to go.
posted by billiebee at 2:27 PM on June 23 [9 favorites]


billiebee, next you'll be telling me I have to hire a safety expert just because I want to operate my limbgrinder machines and headsmasher pistons.
posted by Justinian at 4:08 PM on June 23 [3 favorites]


I know! And remember the good old days when you could send a worker up a building with not a harness or hard hat in sight? Good times. And now these OSHA gits are just ruining everything! I bet stuff like this is just propaganda:
Out of 4,175* worker fatalities in private industry in calendar year 2012, 806 or 19.3% were in construction.
posted by billiebee at 4:46 PM on June 23 [3 favorites]


Duck stampede of 2014.
posted by misozaki at 8:21 PM on June 23


Inside the ant colony
posted by the man of twists and turns at 8:22 PM on July 8


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