Shared Space ("Naked Streets")

[from Gary Cziko 2007.04.09 15:17 CDT]

I have become involved in plans to make my community and campus safer and more inviting to bicyclists and pedestrians. In my research I came across the following article on how fewer traffic controls leads to slower speeds and more safety (sometimes called the “naked streets” approach).

Here is a part of the article that made me think of PCT:

An important foundation stone of
Monderman’s work is the research into
risk and safety of John Adams, professor
of geography at University College

London. The change of behaviour in a
shared space context is related to what
Adams describes as risk compensation
effect, or how humans shift the balance
of risk according to their environment.
If protected from hazards, argues

Adams, humans readjust the risk
threshold. 'You fit a car with better
brakes, people don’t drive the same
way as before and enjoy an extra of
safety, they drive faster and start braking
later. The potential safety benefit of

better brakes in fact becomes a performance
benefit.’

Similarly, traffic management tools
can actually increase the risk of accidents
by absolving drivers from having
to use their intelligence and engage

with their surroundings. ‘Traditional
highway engineering has been based
on the theory that we are completely
oblivious to dangers in the environment
around us,’ Adams points out.
'But that is manifestly not so. Once the

tools are taken away and you put some
uncertainty into the street in terms of
who has right of way, drivers and
pedestrians naturally become more attentive
and engaged, prompting drivers
to reduce speeds and drive more

safely. You redistribute the burden of
risk, giving pedestrians more control.’

It appears that people are controlling for a certain degree of safety. So by making the environment a bit less predictable and appear a bit less safe, drivers slow down and actually make it safer.

–Gary

···

Gary Cziko
Professor
Educational Psychology & English as an International Language
University of Illinois
1310 S. Sixth Street
210F Education Building
Champaign, IL 61820-6990
USA

Telephone +1-217-333-8527
Fax: +1-217-244-7620
e-mail: g-cziko@uiuc.edu

Web: http://garycziko.net
Skype: garyjazz (http://www.skype.com)
Google Talk: gcziko
Amateur Radio: N9MJZ

Founder, Station Manager, Program Director, Chief Engineer and Announcer

The Latino Radio Service of La Casa Cultural Latina
1660 AM on the Urbana-Champaign campus of the University of Illinois
(http://latinoradioservice.org)

Founder and Major Contributor

ATALL Wikibook for
Autonomous Technology-Assisted Language Learning
(http://en.wikibooks.org/wiki/ATALL)

Hold it!

Not everybody would become more attentive and engaged all the time. It's those people/situations that the traffic tools are meant to manage.

Careful driver though I am, I do screw up once in a while, and I've been saved more than once by a properly banked curve or a daylighted intersection.

We have way more than our share of drunk drivers here in New Mexico. If you've read about some of them, you'll see that we really need a better tool to keep them from taking an off-ramp onto the Interstate!

IOW, not all social problems have individual solutions, even with PCT.

Ted

···

--On Monday, April 09, 2007 3:22 PM -0500 Gary Cziko <g-cziko@UIUC.EDU> wrote:

[from Gary Cziko 2007.04.09 15:17 CDT]

I have become involved in plans to make my community and campus safer and
more inviting to bicyclists and pedestrians. In my research I came across
the following article on how fewer traffic controls leads to slower
speeds and more safety (sometimes called the "naked streets" approach).

Here is a part of the article that made me think of PCT:

An important foundation stone of
Monderman's work is the research into
risk and safety of John Adams, professor
of geography at University College
London. The change of behaviour in a
shared space context is related to what
Adams describes as risk compensation
effect, or how humans shift the balance
of risk according to their environment.
If protected from hazards, argues
Adams, humans readjust the risk
threshold. 'You fit a car with better
brakes, people don't drive the same
way as before and enjoy an extra of
safety, they drive faster and start braking
later. The potential safety benefit of
better brakes in fact becomes a performance
benefit.'

Similarly, traffic management tools
can actually increase the risk of accidents
by absolving drivers from having
to use their intelligence and engage
with their surroundings. 'Traditional
highway engineering has been based
on the theory that we are completely
oblivious to dangers in the environment
around us,' Adams points out.
'But that is manifestly not so. Once the
tools are taken away and you put some
uncertainty into the street in terms of
who has right of way, drivers and
pedestrians naturally become more attentive
and engaged, prompting drivers
to reduce speeds and drive more
safely. You redistribute the burden of
risk, giving pedestrians more control.'

It appears that people are controlling for a certain degree of safety. So
by making the environment a bit less predictable and appear a bit less
safe, drivers slow down and actually make it safer.

--Gary

---------------------------------------------------
Gary Cziko
Professor
Educational Psychology & English as an International Language
University of Illinois
1310 S. Sixth Street
210F Education Building
Champaign, IL 61820-6990
USA

Telephone +1-217-333-8527
Fax: +1-217-244-7620
e-mail: g-cziko@uiuc.edu
Web: http://garycziko.net
Skype: garyjazz (http://www.skype.com)
Google Talk: gcziko
Amateur Radio: N9MJZ

Founder, Station Manager, Program Director, Chief Engineer and Announcer
The Latino Radio Service of La Casa Cultural Latina
1660 AM on the Urbana-Champaign campus of the University of Illinois
(http://latinoradioservice.org)

Founder and Major Contributor
ATALL Wikibook for
Autonomous Technology-Assisted Language Learning
(http://en.wikibooks.org/wiki/ATALL)

Ted Cloak
Albuquerque, NM

[From Fred Nickols (2007.04.09.1804 EST)] --

I'd read about this before but it never occurred to me to look at it in terms of PCT. I'd always placed it in the context of complex, self-organizing systems. From a PCT perspective, it also makes sense.

···

--
Regards,

Fred Nickols
Managing Principal
Distance Consulting
nickols@att.net
www.nickols.us

"Assistance at A Distance"
      
-------------- Original message ----------------------
From: Gary Cziko <g-cziko@UIUC.EDU>

[from Gary Cziko 2007.04.09 15:17 CDT]

I have become involved in plans to make my community and campus safer and
more inviting to bicyclists and pedestrians. In my research I came across
the following article on how fewer traffic controls leads to slower speeds
and more safety (sometimes called the "naked streets" approach).

Here is a part of the article that made me think of PCT:

An important foundation stone of
Monderman's work is the research into
risk and safety of John Adams, professor
of geography at University College
London. The change of behaviour in a
shared space context is related to what
Adams describes as risk compensation
effect, or how humans shift the balance
of risk according to their environment.
If protected from hazards, argues
Adams, humans readjust the risk
threshold. 'You fit a car with better
brakes, people don't drive the same
way as before and enjoy an extra of
safety, they drive faster and start braking
later. The potential safety benefit of
better brakes in fact becomes a performance
benefit.'

Similarly, traffic management tools
can actually increase the risk of accidents
by absolving drivers from having
to use their intelligence and engage
with their surroundings. 'Traditional
highway engineering has been based
on the theory that we are completely
oblivious to dangers in the environment
around us,' Adams points out.
'But that is manifestly not so. Once the
tools are taken away and you put some
uncertainty into the street in terms of
who has right of way, drivers and
pedestrians naturally become more attentive
and engaged, prompting drivers
to reduce speeds and drive more
safely. You redistribute the burden of
risk, giving pedestrians more control.'

It appears that people are controlling for a certain degree of safety. So by
making the environment a bit less predictable and appear a bit less safe,
drivers slow down and actually make it safer.

--Gary

---------------------------------------------------
Gary Cziko
Professor
Educational Psychology & English as an International Language
University of Illinois
1310 S. Sixth Street
210F Education Building
Champaign, IL 61820-6990
USA

Telephone +1-217-333-8527
Fax: +1-217-244-7620
e-mail: g-cziko@uiuc.edu
Web: http://garycziko.net
Skype: garyjazz (http://www.skype.com)
Google Talk: gcziko
Amateur Radio: N9MJZ

Founder, Station Manager, Program Director, Chief Engineer and Announcer
The Latino Radio Service of La Casa Cultural Latina
1660 AM on the Urbana-Champaign campus of the University of Illinois
(http://latinoradioservice.org)

Founder and Major Contributor
ATALL Wikibook for
Autonomous Technology-Assisted Language Learning
(http://en.wikibooks.org/wiki/ATALL)

[From Rick Marken (2007.04.09.1630)]

Gary Cziko 2007.04.09 15:17 CDT]

I have become involved in plans to make my community and campus
safer and more inviting to bicyclists and pedestrians. In my research
I came across the following article on how fewer traffic controls leads
to slower speeds and more safety (sometimes called the "naked streets"
approach).

Here is a part of the article that made me think of PCT:
...
If protected from hazards, argues
Adams, humans readjust the risk
threshold.

So the idea is that people control for risk (which I consider
unlikely; risk seems like a pretty difficult thing to perceive). When
you put in hazard protections people become more risky. So is the
evidence of this that when you mandate a risk reduction strategy risk
level is preserved in some wayt? If so, what data do people use to
test this?

Similarly, traffic management tools
can actually increase the risk of accidents
by absolving drivers from having
to use their intelligence and engage
with their surroundings.

Is there data to support this?

'But that is manifestly not so. Once the
tools are taken away and you put some
uncertainty into the street in terms of
who has right of way, drivers and
pedestrians naturally become more attentive
and engaged, prompting drivers
to reduce speeds and drive more
safely. You redistribute the burden of
risk, giving pedestrians more control.'

I'd like to see the data on this. Also, given this guy's theory,
people are always in control, they just have to work harder to
maintain that control when you take away the safety rules. At least,
I think this is what he means. Or does he mean that we actually
control for risk _better_ without the help? If so, how would he
explain that? For example, with or without safety rules, I am
controlling for having zero probability of getting hit by a car. That
reference is the same for me whether I am crossing in a crosswalk or
not. I am more careful (somewhat) when I'm not in a crosswalk but I
hope I am controlling for not getting hit just as well whether I am in
the (probably mythical) safety of the crosswalk or not. I think.

It appears that people are controlling for a certain degree of safety. So by
making the environment a bit less predictable and appear a bit less safe,
drivers slow down and actually make it safer.

So is he saying that you control better for safety without the safety
rules? If so, I'd like to see the evidence for that. My guess is that
safety rules (properly implemented) would improve the feedback
connection between yourself and getting hit by cars (or staying
unhurt if you do get hit). So safety should improve with properly
implemented safety measures. If it doesn't, then the safety department
is probably being run by a libertarian, which is like having the
government run by anti-government conservatives, and you can see how
well _that_ works;-)

Best

Rick

···

--
Richard S. Marken
rsmarken@gmail.com
marken@mindreadings.com

[From Bill Powers (2007.04.10.0530 MDT)]

Rick Marken (2007.04.09.1630) –

[Gary Cziko] It
appears that people are controlling for a certain degree of safety. So by
making the environment a bit less predictable and appear a bit less
safe,

drivers slow down and actually make it safer.

So is he saying that you control better for safety without the
safety

rules? If so, I’d like to see the evidence for that. My guess is
that

safety rules (properly implemented) would improve the feedback

connection between yourself and getting hit by cars (or
staying

unhurt if you do get hit). So safety should improve with properly

implemented safety measures. If it doesn’t, then the safety
department

is probably being run by a libertarian, which is like having the

government run by anti-government conservatives, and you can see how

well that works;-)

I share your skepticism. Control theory would not predict this outcome on
the basis of the properties of a single control system. Increasing
disturbances or reducing loop gain will lead to more error, not less.
Perhaps a multileveled model would suggest a way to believe this
proposition, but I’d have to see it (and test it).
The theory that decreasing traffic controls will reduce accidents says
that the accident rate (above an irreducible minimum) is proportional
(approximately) to the number of traffic controls. Suppose that at a
blind corner, a large convex mirror has been installed so drivers can see
cross-traffic before they get to the corner. According to the proposition
at hand, removing the mirror should decrease the accident rate. But
according to control theory, removing the mirror should make drivers less
able to perceive danger, so they would be less able to avoid a collision
even if they thought about it…
The theory behind the proposition seems to be that if drivers know (at a
higher level) that they can’t see oncoming traffic, they will be more
cautious at the corner. But if they can’t see any danger, or have never
passed that corner before, why should they be more vigilant than usual?
The only possible answer is that as they approach the corner, they
imagine what might happen, and react to the resulting error by slowing
down and being sure they can see cross-traffic before they enter the
intersection. So now safety depends on exactly what drivers imagine as
they approach the corner. Is imagination more reliable than perception?
Not usually. How many rear-end collisions are caused by drivers whose
imaginations lead them to slow to a timid crawl at every
intersection?
The crux of the matter is what is meant by the word “drivers.”
That word obviously does not mean every single driver without exception,
although that is the impression that the use of this class-term is meant
to convey (conventional psychologists and sociologists perfected this way
of removing uncertainty long ago). It really means “some
drivers,” where “some” means a fraction between 0 and 1.
If the fraction is close to one, then almost all people will believe the
proposition. As the fraction drops below 1, the number of people who
believe the proposition will, presumably, decrease, if they are not
conventional psychologists or sociologists.
In fact, we must refer to the Grand Unified Theory of Social Science to
find the correct prediction of the results of doing as the proposition
suggests. The Grand Unified Theory of Social Science is that given any
statistical generalization about what people will do, we can reliably
predict that some of them will do it and the rest of them won’t. So we
can say with confidence that if traffic control devices are removed, some
drivers will become more cautious and drive more safely, and the rest of
them will be divided among those whose behavior is unchanged and those
who drive even less safely than before.
Clearly, those who ignore traffic control devices altogether will not
change the way they drive at all. Those who, for fear of punishment, were
somewhat slowed by red traffic lights or stop signs or who slowed down
upon seeing warnings like “blind corner ahead” or “bridge
out” or “yield to bicycle lane when turning” will not slow
down any more. In fact, only the drivers who actively look for signs of
danger, whether aided by traffic control devices or not, will
perceive a lack of indicators as meaning increased danger, and slow down
or look more carefully.
The question, of course, is the size of each population and one’s
attitude toward each. It could be argued by fans of natural selection
that removing traffic control devices will eventually remove the
population with unchanged or worsened driving habits, at the expense of a
temporary increase in accidents but with an eventual overall reduction
(note, however, that no driver learns anything from being killed in a car
accident). Unfortunately, we can’t be sure that bad driving is inherited,
and anyway drivers are not the only people in cars and bad drivers do not
collide only with other bad drivers, so if one is concerned about the
innocent, this will not be acceptable.
Obviously, if installing some purported safety device is followed by an
increase in the accident rate, AND removing the safety device is followed
by a decrease in the accident rate, we can reasonably conclude that
something about the design or placement of this device leads to more
accidents. Perhaps it is demanding too much attention from the drivers,
like a road sign containing 100 words. The sign itself may obscure vision
of cross traffic. The choices are then to redesign the device, reconsider
its placement, or cease using it altogether. But as we all know, it would
be just as much a mistake to conclude that an observed increase in the
accident rate was caused by a new traffic control device as it would be
to conclude that an observed decrease in the accident rate was caused by
the new traffic control device. There are too many other variables that
offer alternative explanations. One needs more than a few instances to
draw a conclusion about all possible instances. And one needs to think at
least a little bit instead of just using statistics.
We must also realize, and I’m sure we all do, that sometimes ad
hominem
arguments are justifiable. Hitler’s treatment of the Jews can
be criticised on the basis that he was acting from personal beliefs and
hatreds, so even before we investigate, we can safely ignore the
“facts” he offered as excuses. It does make a difference
whether a movie critic receives a salary from a movie studio, or whether
a person who sneers at global warming happens to operate a coal mine. By
the same token, it is not unfair to consider whether the person proposing
the removal of traffic control signs considers all laws and rules to be
impediments to his personal freedom (he is probably already a menace on
the road). Goals and beliefs determine whether perceptions are considered
desirable or undesirable, or even which ones will be taken as evidence or
ignored. Those who argue mainly from private beliefs and attitudes tend
to sift the evidence to select positive instances that support their
positions. Of course investigation of the facts is always called for:
even an idiot can be right sometimes. But where it can be seen that there
is a very likely bias, one is justified in doubting any purported facts
offered without proof.

Show me that when the traffic control device was removed, accidents went
down again. Show me that it was not something about bad design or bad
placement that was responsible. Show me that some other event, such as
opening of a sports arena or a roadside bar or closure of an alternate
route, was not an equally likely culprit. And explain to me exactly
how the proposed effect occurs. Then I’ll believe it.

Best.

Bill P.

[From Rick Marken (2007.04.10.0920)]

Bill Powers (2007.04.10.0530 MDT)--

Rick Marken (2007.04.09.1630) --

So is he saying that you control better for safety without the safety
rules? If so, I'd like to see the evidence for that. My guess is that
safety rules (properly implemented) would improve the feedback
connection between yourself and getting hit by cars (or staying
unhurt if you do get hit). So safety should improve with properly
implemented safety measures. If it doesn't, then the safety department
is probably being run by a libertarian, which is like having the
government run by anti-government conservatives, and you can see how
well _that_ works;-)

I share your skepticism.

Thanks. And your post says just what I wanted to say, only better than
I could say it, of course. Great points.

Best

Rick

···

--
Richard S. Marken
rsmarken@gmail.com
marken@mindreadings.com

In a message dated 4/10/2007 8:58:19 A.M. Eastern Standard Time, powers_w@FRONTIER.NET writes:

Show me that when the traffic control device was removed, accidents went down again. Show me that it was not something about bad design or bad placement that was responsible. Show me that some other event, such as opening of a sports arena or a roadside bar or closure of an alternate route, was not an equally likely culprit. And explain to me exactly how the proposed effect occurs. Then I’ll believe it.

For those interested, some of the information desired can be obtained by looking at Wikipedia under the heading “Shared Space”.

With Regards,

Richard Pfau

···

See what’s free at AOL.com.

[From Bill Powers (2007.04.11.0910 MDT)]

Richard Pfau (2007.04.11) –

In a message dated 4/10/2007 8:58:19
A.M. Eastern Standard Time, powers_w@FRONTIER.NET writes:

Show me that when the traffic
control device was removed, accidents went down again. Show me that it
was not something about bad design or bad placement that was responsible.
Show me that some other event, such as opening of a sports arena or a
roadside bar or closure of an alternate route, was not an equally
likely culprit. And explain to me exactly how the proposed effect occurs.
Then I’ll believe it.

For those interested, some of the information desired can be
obtained by looking at Wikipedia under the heading “Shared
Space”.

Well, I don’t believe it yet, but what I see in the pages you cited is an
experiment in progress, and that’s a good thing. I didn’t find anything
about adding and then removing traffic control devices to check the
effect, but the general picture is pretty attractive and since accidents
are sharply down in some of the areas, I don’t see any reason to stop the
experiments. There’s an awful lot of “people” do this and
“people” do that, but maybe some researchers are actually
keeping track of the numbers. I hope so.

Best.

Bill P.

[Martin Taylor 2007.04.14.22.40]

[From Bill Powers (2007.04.10.0530 MDT)]

Rick Marken (2007.04.09.1630) --

[Gary Cziko] It appears that people are controlling for a certain degree of safety. So by making the environment a bit less predictable and appear a bit less safe,
drivers slow down and actually make it safer.

So is he saying that you control better for safety without the safety
rules? If so, I'd like to see the evidence for that. My guess is that
safety rules (properly implemented) would improve the feedback
connection between yourself and getting hit by cars (or staying
unhurt if you do get hit). So safety should improve with properly
implemented safety measures. If it doesn't, then the safety department
is probably being run by a libertarian, which is like having the
government run by anti-government conservatives, and you can see how
well _that_ works;-)

I share your skepticism. Control theory would not predict this outcome on the basis of the properties of a single control system. Increasing disturbances or reducing loop gain will lead to more error, not less. Perhaps a multileveled model would suggest a way to believe this proposition, but I'd have to see it (and test it).

It's funny, but I was recalling this Dutch "experiment" when I was driving on an expressway in Victoria State, Australia, last week. I felt it was the most dangerous highway I had ever been on. In Victoria, they enforce the speed limit VERY strictly, and on this six-lane motorway, the speed limit was 100 kph. Almost every car was going within 1 or 2 kph of the limit.

Although I was driving the highway on Easter Friday and Sunday, with very light traffic, I have never felt so nervous. Why? Subjectively, there were three reasons, two of which apply to the more general case.

1. The traffic pattern changed VERY slowly. If I was beside a car, it might take minutes to get past it, or I would have to brake to get behind it to change lanes. Because of the severe enforcement, reminded frequently by signs like "Speeding -- sever fines and loss of licence", I would not dare accelerate to 105 kph. So it would be very hard safely to take emergency action if required. One would need a lot of notice that the emergency would soon appear.

2. Related to the above, in the traffic patterns, NOTHING HAPPENS, except that people join and leave the motorway at interchanges. One is lulled into a false sense of security. Being aware of this (see other thread between Bill and Elizabeth), I tried to be especially attentive, but it's so easy to allow one's attention to wander away from the traffic and to think of other things. On a normal highway, this hardly ever happens.

3. Specific to the multi-lane highway situation: There is VERY poor lane discipline when the speed limit is so rigidly controlled, despite a multitude of signs that say "Keep left unless passing". But if one is driving 99 kph, one feels entitled to use any lane, as nobody should be expected to pass. Nobody can go more tha 100, and most drivers to give their speedometers credit for 1 kph of error (and the highway has places with radar that shows your actual speed, so they know, pretty well, what their speed is.

Paradoxically, or perhaps not, I have always felt safer on an autobahn with no speed limits, at about 170 kph than at home where the speed limit is 100, but most drivers go between 110 and 130; and I feel much safer at home than on that highway in Australia. I'd hate to drive that road in heavy traffic!

...
Obviously, if installing some purported safety device is followed by an increase in the accident rate, AND removing the safety device is followed by a decrease in the accident rate, we can reasonably conclude that something about the design or placement of this device leads to more accidents. Perhaps it is demanding too much attention from the drivers, like a road sign containing 100 words.

Or it removes the need to pay attention. Although "boring" isn't commonly used in a PCT context, it can be important. Think of the Nullabor highwayin South Australia, with 150 km streatches of dead straight rod on one side of a railway line, terminated by a switch to the other side of the line and a ile of wrecked cars. Or, think of the old (1940's to 60's) studies of "vigilance" in which signals that are theoretically very easy to see are completely missed when the person has been watching for more than a few minutes and there have been very few actual signals.

Maybe the "attention" thread might be augmented by some discussion on the PCT-relevant meaning of boredom. It's a real enough experience, when one seems not to have enough consciously aware controlling to do. And I think it relates to the question of whether highways can be too highly controlled -- excess safety precautions apparently making for more danger. It also my relate to the question of whether we do actually control for a certain level of risk, as sometimes is suggested.

My personal view on speed limits is that there is sometimes a need for them, but only in cases where there is a danger that is not obvious to the driver unfamiliar with the road. On severely winding roads in New Zealand, I found the speed cautions on the curves very useful, as they allowed me to judge what kind of a curve lay beyond the part of the road I could see. They weren't speed limts, but I think there would have been justification to make them so. Otherwise, I think mandatory speed limits tend to make people think that the limit speed is safe, when it often isn't. They use the speed limit to set their reference level for driving speed, rather than using their perception of the road conditions.

CSGnet is seldom boring!

Martin

It’s funny, but I was recalling
this Dutch “experiment” when I was driving on an expressway in
Victoria State, Australia, last week. I felt it was the most dangerous
highway I had ever been on. In Victoria, they enforce the speed limit
VERY strictly, and on this six-lane motorway, the speed limit was 100
kph. Almost every car was going within 1 or 2 kph of the
limit.
[From Bill Powers (2007.04.14.2158 MDT)]

Martin Taylor 2007.04.14.22.40 –

Well, according to the theory that seems to lie behind the Dutch
experiment, that should mean that you were driving more safely than you
would have done on a highway where you felt comfortable and unstressed.
The idea is apparently that people become much more cautious in their
driving when they are aware that there is danger and know it is up to
them to avoid it.

Although I was
driving the highway on Easter Friday and Sunday, with very light traffic,
I have never felt so nervous.

But that’s good, isn’t it? You are not supposed to feel safe, but just
the opposite, because that will make you more vigilant and sensitive to
potential danger.

What you are arguing is that the Australian traffic control methods are
actually badly designed because they allow no leeway for adjustments like
temporarily speeding up to pass or avoid a collision. The severe
penalties create a conflict between safety and losing your license. That
does not say that a properly-designed system of traffic control would not
be safer.

I have the word of a Pennsylvania state trooper that “We give 'em 5,
they take 10, and we nail 'em on 15.” That’s in miles per hour, so
we’re talking about a rather elastic speed limit in comparison with the
one you report. This means that in Pennsylvania there must be more
accidents per car-mile than in Australia, because driving is less
stressful in Pennsylvania. I wonder if that is true.

It may be that the Dutch experiment has lowered traffic accidents, but I
seriously doubt whether the real reason is the one they give.

Best,

Bill P.