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Obstacles Near Emergency Exits Speed Evacuation 199

BuzzSkyline writes "Despite fire codes that require emergency exits be clear of obstacles, some types of obstacles actually speed evacuation. The counterintuitive conclusion resulted from a series of experiments performed at a TV studio in Japan. Researchers from the University of Tokyo asked 50 volunteers to exit the studio through a narrow door. Video tapes of the experiments show that people made it out quickest when a pole was placed about 30 degrees to one side of the exit. The lead researcher believes an obstacle reduces jamming and friction among people in crowds by decreasing conflicts as the crowd presses toward the exit. A paper describing the research is scheduled to appear in the journal Physical Review E in September, but a preprint is available on the Physics Arxiv."
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Obstacles Near Emergency Exits Speed Evacuation

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  • I Could Be Wrong... (Score:1, Interesting)

    by Anonymous Coward on Saturday August 22, 2009 @12:40PM (#29156035)

    ...but I remember reading articles about this in Scientific American or Discover years and years ago. I think research into this happened back in the late '80s, after incidents like the NYC "Happy Land" fire, where it was found placing a "grid" of poles near the exits would actually prevent people from stampeding, trampling, and blocking the exits. (Yes, I know it's Slashdot... so I'm not surprised it's actually old news...)

  • Re:Old news (Score:1, Interesting)

    by Anonymous Coward on Saturday August 22, 2009 @12:53PM (#29156107)

    I'm looking. I distinctly remember a German TV science show which demonstrated the effect of an advertising column like obstruction in front of an emergency exit years ago.

    There are also applications in storage silos for granulate in industrial settings, where nozzle designs use similar effects to reduce the number of jams.

  • by Anonymous Coward on Saturday August 22, 2009 @01:03PM (#29156173)

    There should be MORE poles. So while the crowd is pushing on the pole, folks get on the other side and on their way to safety.

    I wonder if during a panic, if it would be possible to crowd surf your way to safety. Or walk on their shoulders?

  • by shoor ( 33382 ) on Saturday August 22, 2009 @01:03PM (#29156175)

    There's various places in fluid dynamics where 'obstacles' are put to improve flow aren't there? Those cone shaped things in jet engines for instance (and falcon's have similar cone shaped things in their nostrils.) Maybe this is like that.

  • by Miksa ( 300587 ) on Saturday August 22, 2009 @01:24PM (#29156327)

    I think the bus drivers in local traffic seem to have come up with the same solution. They usually drive a few meters past the bus stop, so most of the people have to walk beside the bus forming a line naturally before stepping in. Always makes you wonder why more people don't stand after the stop at the point where the bus door will be. Guess that's people for you.

  • by shma ( 863063 ) on Saturday August 22, 2009 @01:29PM (#29156363)
    They are not suggesting making the exit smaller, they are suggesting that an obstacle is placed further from the door to reduce the number of paths to the door and keep the number of people trying to push through the exit at any given time to a minimum. See Fig. 18 in the arXiv paper if you want to look at a diagram of this.

    Interestingly enough, these results seem to have been known for a while (probably based on anecdotal evidence). I distinctly remember my fluid mechanics teacher telling our class almost exactly the same thing in 2006, explaining that a crowd headed for the exit behaved in similar ways to a fluid trying to pass through a small opening.
  • by Anonymous Coward on Saturday August 22, 2009 @02:02PM (#29156551)

    I've heard that one normally recruits people from local sport teams for these kind of trials. Competitive folks, who also tend to have good insurances.

  • by Gorobei ( 127755 ) on Saturday August 22, 2009 @02:16PM (#29156629)

    Oh, and design the exit assembly areas so as to encourage dispersion from the final choke point at the exit: ideally, have the exit open to an amphitheater like shape so people will walk/run downhill/in various directions. Add attractors to get them away from the choke point fast: like, big sign advertising free beer 100 yards off to the side (seriously.)

  • Re:Old news (Score:3, Interesting)

    by speedtux ( 1307149 ) on Saturday August 22, 2009 @06:25PM (#29158289)

    That's a simulation; the work from Tokyo is tests with real people.

    So, the principle has been articulated, but this work is still a new contribution.

  • by Anonymous Coward on Saturday August 22, 2009 @08:15PM (#29159225)

    This reminds me of a mathematical thesis presented here in Manchester by some German fella. He showed that putting an object in front of the exit would drastically improve chances of survival. He even presented his findings using Flash, with dots to represent people with very basic AI fleeing from a wall of flame. He showed a few simulations of the little flash program he had written and, lo and behold, placing a large circular object in front of the exit saved a great many dots from a premature death at the hands of the approaching fire wall, or from being crushed to death.

Trap full -- please empty.