For a Quick Exit, Just Block the Fire Door | Hacker News Reader

For a Quick Exit, Just Block the Fire Door

physicsbuzz.physicscentral.com

54 pointstimf16 comments

Reminds me of a subway station in Beijing. It's one of the more popular ones, an exchange between major lines, and once people exit the train they need to go down stairs to get to the other platform. Just in front of the stairs is an enormous shoulder-height roadblock, ostentatiously there to prevent the mass from just shoving people down the stairs.

Oddly, though, it also makes the traffic just breeze through that part of the station. People near the obstruction form nice orderly lines and, knowing that it's totally useless to try to push by, keep them.

Later down the stairs there's a 90 degree turn and immediately the crowd slows down again

Applying science to things most people don't even think about = awesome.

Cool, but I think the test should be done in full fight/flight conditions, would it change the result? Any ethical ways to even do that?

(rigging up an A/B situation on two sides of a theater and hoping it catches on fire one day?)

Any ethical ways to even do that?

Pick any two exits at any large train station in Japan and perform "construction" on them during the morning rush hour, which gives you carte blanche to alter their topography any way you see fit. At that time of day, you've got densities and speeds approaching "fire in a crowded theatre" anyhow.

The number of people who pass through, e.g., a single point in Tokyo Station between 8 and 9 AM every single day staggers the imagination if you've never seen it.

How about, "the first ten people to exit get $50"?

Really neat idea.

I'd say you want to give more people an incentive to get out, since part of the dynamics will be hour the middle and back of the crowd work, but I really like the idea of the cash reward.

The only difficulty will be to make it big enough that people feel the same stress as when they think there is a fire but not so big as to bankrupt the study :)

Yeah, you are exactly right. After the people in the back see 10 people exit, they won't care anymore.

How about, start with n dollars, and as time goes by, decrement $n. At the end, $n is split amongst all participants. So in this case, there is an incentive for people at the end to get out quickly, as the amount of money they get depends upon how fast they get out. (There is no "end" until everyone is out.)

This might be closer to exiting a burning building, but it is still not quite the same. (People want money, but probably not as much as not dying in a fire.)

Yeah, thats probably as close we'll get. You want to get each person to think of themselves first. This may not cover the parent with young kids scenario, but it seems pretty close/good.

Now... the researchers are going to run into issues if someone desperate for money decides to punch some old lady in the face to get out first and claim his $50...

Not only has this been done, but they have done studies to optimise the amount offered, and the number of people who get it. In the UK it's five pounds, in the USA it's about $10, in both cases to the first 40 (although the distrubtion is quite flat, and anywhere from 30 to 50 works).

If you offer more, the motivation drops off. There are several "explanations" offered, but no one really seems to understand why the optimal amount is apparently so low.

Maybe people will disbelieve they'll get paid if the amounts are unreasonably high, but they can expect a small amount to be thrown away on a test like this ?

"We're testing the fire exits. If we're able to empty the theater in our (undisclosed) target time, there's a draw of $(big_price) among all of you."

I had a discussion with a flight safety person regarding this. He was talking about how test evacuations are very unsympathetic - people will literally step on their own grandmother to get out quickly. There was zero compassion, noone helping others - because it's a game, not a life-and-death situation. I think, and he agreed, that in an actual life and death situation, there will be a certain number of "heroes", people stopping to help others.

But to answer GP, it's probably exceedingly difficult to test life-and-death situations in a both correct and ethical manner.

The only issue I can see here is people not understanding the science of it, And only having it make them more anxious or induce panic at not being able to easily get to the exit.

I wonder if this could be applied to car traffic, especially in emerging countries, where traffic is at best rush hour conditions during most of the day.

It already is: http://en.wikipedia.org/wiki/Roundabout

Unfortunately, roundabouts don't work here in Manila. We have a couple here and it's gridlock. I think car traffic engineering has many universal qualities but also quirks that need to be tweaked per country.

"the next step is to program models of people intelligent enough to self-organize into a line"

Goog luck with that...while they're at it, they might as well program Santa Claus and the Easter Bunny!

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