Hi benjaminb,
When two pedestrians approach, each assumes that the other will walk
in the direction that they are looking. This is generally a safe
assumption, as we normally look in the direction we intend to walk.
But there's a catch! To determine which way the other pedestrian is
looking, we must glance at them. If both pedestrians glance at each
other at the same time, the "avoidance dance" is likely to occur. But
in most cases, the "glancing" technique works to avoid collisions.
It's easy to test this hypothesis. The next time you find yourself
walking towards someone, simply look to the right and walk to the
left. The oncoming pedestrian will almost always bump into you and
apologise profusely.
This explanation was told to me many years ago, and I believe it to be
correct. However, there's not a great deal of supporting evidence
online.
In one experiment, Collett & Marsh observed pedestrians at Oxford
Circus. They observed that when a male passed a female, the woman
would be more likely to break step and move out of the way. That's
consistent with your observation that your girlfriend always moves out
of the way, and your buddy Mike never does.
Collett & Marsh (1981) Patterns of Public Behavior: Collision
avoidance on a pedestrian crossing, in A. Kendon (Ed) "Non-verbal
communucation interaction and gesture." The Hague: Mouton Press
That article does not appear to be available online, but it is briefly
mentioned in two places:
Some Notes on Collett & Marsh
http://www.unn.ac.uk/academic/ss/psychology/resource/py014/00/p3/coll.html
Collision avoidance
http://www.unn.ac.uk/academic/ss/psychology/resource/py014/00/p3/p3th.html
Dirk Hellbing and Peter Molnar study crowd behavior. They were
particularly interested in the way in which "lanes" form in busy
crowds. Their work is discussed in a July 15 2000 New Scientist
article "It's flaming freezing!" The article is only available to
subscribers, but an excerpt appears here:
Excerpted from "It's flaming freezing"
http://vorlon.cwru.edu/~axc/temp/helbing.html
Dirk Hellbing's "Publications" page lists several papers on models of
pedestrian movement:
http://www.tu-dresden.de/vkiwv/vwista/sta1_hp.htm
Hellbing has modeled pedestrian movement by a series of equations
based on what he calls "social forces". These are the desire to move
towards a goal, the desire to keep a distance from other pedestrians
and borders, and "attractive effects". Computer simulations based on
these equations "show that the social forces model is capable of
describing the self-organization of ... pedestrian behavior
realistically":
Social Force Model for Pedestrian Dynamics
http://arxiv.org/abs/cond-mat/9805244
In a masters thesis by Franck Feurtey of the University of Tokyo he
develops "an algorithm to model the collision avoidance behavior of
pedestrians ... and made a comparison with real-world data."
Franck Feurtey found that "the people coming ahead are usually briefly
glanced at, and then discarded, when a collision is likely to happen,
a kind of communication occurs involving the emissions of signs to
allow the other to discover one's purpose, and an establishment point,
when both parties acknowledge."
Simulating the Collision Avoidance Behavior of Pedestrians
http://www.logos.t.u-tokyo.ac.jp/~franck/research_sum.htm
I suspect the "brief glance" Franck refers to is the one where each
pedestrian checks which way the other is looking.
A lighthearted discussion at New Scientist starts with a drinker's
observation that he tends to stumble towards the left, and is followed
by a suggestion that most people have a tendency to move towards the
left when walking:
The Last Word Science Questions and Answers
http://www.newscientist.com/lastword/article.jsp?id=lw175
Some pedestrians follow a "sidewalk etiquette", always passing on the
right or left (according to the driving rules in their country).
Indeed, a few cities even have a center-line painted onto the walkway
in particularly busy areas. In his syndicated column, Dale McFeatters
laments the dilution of sidewalk etiquette:
Dale McFeatters: American sidewalk etiquette showing cracks
http://www.naplesnews.com/02/07/perspective/d805985a.htm
Anyway, I suggest you try the "hypothesis test" that I mention near
the top of this answer. I think you'll be convinced!
Additional links:
Sidewalk etiquette - some musings from a Canadian perspective
http://www.perplections.com/annals/annals%20sidewalk%20etiquette.htm
San Cristobal de las Casas: Pedestrian Behavior (in Mexico)
http://icsdev.soe.umich.edu/confur/discuss/reader/fall/ody$d1d4d3af4dabe79d5a0950fc0cba38d0
Space invaders (musings from an american in Asia)
http://www.homestead.com/bigmouthgirl/SpaceIn.html
Google search strategy:
walking collide sidewalk OR pavement OR footpath
://www.google.com/search?q=walking%20collide%20sidewalk%20OR%20pavement%20OR%20footpath
"people collide" walking
://www.google.com/search?q=%22people+collide%22+walking
"people bump into each other"
://www.google.com/search?q=%22people+bump+into+each+other%22
"Dirk Helbing" "Peter Molnar" pedestrian
://www.google.com/search?q=%22Dirk+Helbing%22+%22Peter+Molnar%22+pedestrian
walking "moves out of the way" collide OR bump step side
://www.google.com/search?q=walking+%22moves+out+of+the+way%22+collide+OR+bump+step+side
"sidewalk OR pavement OR footpath etiquette"
://www.google.com/search?q=%22sidewalk+OR+pavement+OR+footpath+etiquette%22
Regards,
eiffel-ga |
Request for Answer Clarification by
benjaminb-ga
on
03 Sep 2002 03:19 PDT
Thank you for your research. It was most interesting. I however
still have that nagging feeling that I had when I submitted my
question. What makes some people move out of the way more than
others?
You’ve done well in finding and summarizing sidewalk walking patterns
and models, specifically for when there are crowds on the streets. My
question is however much more basic and fundamental. For two people,
what makes one person move out of the way of the other? My girlfriend
moves out of the way all the time. My friend Mike doesn’t move out of
the way, ever. Yet, no-one walks into him. If the two of them were
to approach each other, she would invariably be the one that moves.
What’s different about them. How does this invisible intuitive
mechanism work that allows the one to be a walker and the other a
mover? Or do we all, as the models suggest, walk around randomly
where the patterns that form have no bearing on our social selves.
|
Clarification of Answer by
eiffel-ga
on
03 Sep 2002 06:28 PDT
Hi benjaminb,
> What makes some people move out of the way more than others?
There's a straightforward explanation for this which is consistent
with the theory that we glance at oncoming pedestrians, then assume
they will walk in the direction that they are looking, and adjust our
course accordingly.
Each person tends to check for obstacles a certain distance ahead. For
example, I might tend to glance three meters ahead. Someone else might
have a walking style where they do not glance so far ahead. By the
time this person identifies an oncoming pedestrian, that oncomer has
probably already seen them and has made adjustments.
So, the people who tend to look the furthest ahead are those who will
take the most "avoidance action", and those who look the shortest
distance ahead will rarely have to adjust their course.
> My girlfriend moves out of the way all the time.
It's interesting that this matches the observation of Collett & Marsh,
who found that females were more likely to break step and move out of
the way. Perhaps females tend to scan further ahead for obstacles
whilst walking.
> My friend Mike doesn't move out of the way, ever. Yet, no-one walks
into him.
Try it! Walk down a busy street. Look straight ahead, and not at any
oncomers. They'll eventually glance at you, and will move aside. Just
hope you don't meet Mike!
Actually, even Mike probably has a personal scanning distance. It's
likely that Mike's scanning distance is notably shorter than that of
most other people.
Regards,
eiffel-ga
|
Request for Answer Clarification by
benjaminb-ga
on
04 Sep 2002 02:52 PDT
You've still missed it :( I've read through your previous questions,
and I see that you are regarded as a superb researcher. I still
however feel that you have missed the point.
In all the information, I still see no link between the personality of
the walkers and their tendency to veer off path. The only link that
you have mentioned (and from the way is reads, it is deduced) is that
the more shortsighted a person, the more likely he is not to veer.
Come on – this can’t be true. I can’t believe that there isn’t a link
between a person’s sense of self and their predisposition to move.
I asked my girlfriend what her opinion was. She recons that veering
is based on primal animal instincts of the smaller less dominant to
move out of the way of the stronger, more dominant.
Do you honestly believe that the only correlation between her tendency
to veer versus Mike’s tendency not to is based on the fact that Mike
looks down at his nose and she looks off into the distance?
Anyway, I don’t expect you to spend any more time on this question, as
I think that you’ve done your five bucks worth of work. But, I’m
tempted to rate it as a three-star, as I feel that it’s missed the
point.
|
Clarification of Answer by
eiffel-ga
on
04 Sep 2002 04:38 PDT
Hi benjaminb,
Sorry that I seem to have missed your point - but thanks for giving me
the opportunity to get a little closer. That's the purpose of the
"clarification" function.
I did not intend to suggest that there is no link between "a person' s
sense of self and their predisposition to move". I just hadn't picked
up from your question that you were seeking this. I guess I saw the
word "mechanism" in your question and went off on a tangent. Sorry!
The "glance and see which way the oncomer is looking" is the MECHANISM
by which collisions are avoided amongst the large number of people
present. The "glancing distance" accounts for the way in which certain
people will habitually be the ones who step to the side.
I would certainly agree that a person's habitual "glancing distance"
is influenced by their sense of self, the size of the personal space
desired by that person, and their personality.
However, I cannot find any research which confirms this, nor can I
think of an easy test that one can perform oneself.
As to whether these are "primal" or "cultural" causes at play, I
suspect that the cultural cause must be pretty strong. Two of the
pages listed in the original answer (describing pedestrian behavior in
other countries) mention that collisions are more common in countries
where people do not have such a wide "personal space". Here's one from
Russia, where apparently pedestrians are more likely to elbow you out
of the way:
"The Asian Reporter Columns"
http://www.asianreporter.com/stories/anotherasia/aa-24-02.htm
You are right when you say that the "glancing mechanism" that I
described is only 'deduced' from the available online literature. But
it's a very easy to test for yourself on a busy street.
I did read the "glancing mechanism" explanation in print many years
ago, although I have no idea where. The print article ended on a
lighthearted note suggesting that a male could exploit this mechanism
to force an attractive female to bump into him - and in my teenage
years I did try this once for the fun of it (successfully).
I did locate what seems to be a fairly definitive study carried out by
psychologists:
Cutting, J.E., Vishton, P.M., & Braren, P.A. (1995). How we avoid
collisions with stationary and moving obstacles. Psychological Review,
102(4), 627-651.
http://www2.psych.cornell.edu/cutting/pub/psychrev1995.pdf
That study is based on "mechanisms" such as retinal movement. The
authors claim that it models the real world favorably. However, that
study does not include the word "social" anywhere in its text,
although they do make mention of "personal space".
The study features an extensive bibliography, of several hundred
articles, none of which appears to address the social aspects of
pedestrian collision avoidance. Possibly there is no such published
research - or maybe I've not found it yet. Naturally, if I do find
something more I will post it here.
Regards,
eiffel-ga
|
