Everything we know about traffic-calming is wrong

On 22/6/04 1:19 pm, in article
[email hidden], "Velvet"

Quoted message said:

Quoted message said:

Quoted message said:

By removing all signage and lines, I'm sure there would
be a lot of drivers who would feel too confused and
intimidated to drive ever again. This could be good, but
consider that those who stick it out and succeed in
driving successfully in that sort of environment will be
those who already have a tendancy to intimidate other
drivers into giving way to them, letting them pass, and
taking any other sort of action to avoid an accident
that would otherwise result.

Quoted message said:

Quoted message said:

I wonder why, then, when this has been tried, the result
has been a reduction in speeds and a substantial
reduction in crashes?

Quoted message said:

I'd hazard a guess that it's because of unfamiliarity. How
long was it left in place for, and to what extent were
signs and markings removed?

I'd hazard a different guess.

As these areas tend to be residential, the concept is then
that rather than having 'my space' and 'your space' where it
is your fault for encroaching my space, the concept is 'our
space' and all may be using it.

Whatever it is, it works.

..d

Velvet said:

Quoted message said:

Quoted message said:

By removing all signage and lines, I'm sure there would
be a lot of drivers who would feel too confused and
intimidated to drive ever again. This could be good, but
consider that those who stick it out and succeed in
driving successfully in that sort of environment will be
those who already have a tendancy to intimidate other
drivers into giving way to them, letting them pass, and
taking any other sort of action to avoid an accident
that would otherwise result.

Quoted message said:

Quoted message said:

I wonder why, then, when this has been tried, the result
has been a reduction in speeds and a substantial
reduction in crashes?

Quoted message said:

I'd hazard a guess that it's because of unfamiliarity. How
long was it left in place for, and to what extent were
signs and markings removed?

Unfamiliarity and the fact that greater concentration is
necessary. Nor is that a new thing - JS Dean commented on in
in 1946! The signs and markings were expunged pretty much
completely, as I recall; certainly centrelines and give way
markings, and in some cases they've tried removing traffic
lights as well.

Years ago a set of lights was demolishedby a truck in St
Albans (King Harry if anyone knows it). The lead time on a
new controller was months, so the council sent a man with a
pot of paint and they made it a double mini roundabout.
Traffic flow improved immediately, and the lights were never
reinstated.

--
Guy
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Just zis Guy said:

Actually the grip on my current car is so good that I
haven't managed to trigger the ABS yet, even when
I've tried.

Wet grass?
--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
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Velvet said:

If we go down the road of saying risk compensation
nullifies the safety aspects, then that has to be applied
to absolutely everything else.

Quoted message said:

Builders shouldn't wear hard hats, cos, obviously, they'll
take less care than if they do. That'll save lots of
lives, oh yes.

The secret to a successful safety measure, given risk
compensation, is that it should be better than it seems to
be. One of the many points on which cycle helmets fail.

Quoted message said:

Oh, and we'd better not let climbers wear ropes/harnesses
either, cos they might not be so careful about not falling
off if they have them.

Climbers don't use safety gear to be safer, they use safety
gear in order to be able to climb much harder pitches with
the same level of risk. Opposite approach.

--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
["]http://www.dai.ed.ac.uk/homes/cam/]

On Tue, 22 Jun 2004 14:16:12 +0000 (UTC) someone who may be
[email hidden] (Chris Malcolm) wrote this:-

Quoted message said:

Velvet <[email hidden]> writes:

Quoted message said:

Quoted message said:

Builders shouldn't wear hard hats, cos, obviously, they'll
take less care than if they do.

It is correct that they take less care.

Quoted message said:

Quoted message said:

That'll save lots of lives, oh yes.

However, that does not necessarily follow. Risk compensation
is a subtle thing.

Quoted message said:

The secret to a successful safety measure, given risk
compensation, is that it should be better than it
seems to be.

Agreed.

--
David Hansen, Edinburgh | PGP email preferred-key number
F566DA0E I will always explain revoked keys, unless the UK
government prevents me using the RIP Act 2000.

Chris Malcolm said:

Quoted message said:

Actually the grip on my current car is so good that I
haven't managed to trigger the ABS yet, even when
I've tried.

Quoted message said:

Wet grass?

According to Pete that makes you drive slower, though...

--
Guy
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On Tue, 22 Jun 2004 11:55:07 +0100, "Just zis Guy, you know?"
<[email hidden]> wrote (more or less):

Quoted message said:

Velvet said:

You very carefully say 'its not there to stop you
quicker', I say in a given circumstance it will. We
aren't talking about the same thing, and I know it, and I
think you know it too.

Possibly. I guess it's like the difference between "my
helmet saved my life" and "helmets save lives".

Quoted message said:

I dislike generalisations, and the 'ABS wont make you
stop faster' is just such a generalisation. It's become
abundantly clear you're only interested in the
generalisation though.

I am indeed. The generalisation is what people will be
thinking about as they consume the safety benefit of ABS as
a performance benefit. "I can stop quicker thanks to ABS"
therefore "I don't need to leave as much space".

...

Quoted message said:

Like the two old women exchanging words across the
Shambles, we are arguing from different premises.

...

But Velvet's generalisation is more generaly true that your
generalisation, Guy.

You say Guy 'ABS is not there to shorten braking distances'.
In fact it does.

/Generally/ by a lot for unskilled brakers who will lock up
the tyres. (This was its original selling point. Unlocked
wheels stop faster than locked wheels).

/Generally/ by a bit for highly skilled brakers who can keep
their wheels from locking up, but only by using the lowest
common non-locking braking force on all four wheels

It also will /generally/ extend braking distances on loose
surfaces where locked wheels may create wedges in front of
the themselves.

Your main objection seems to be that if folk think of ABS as
a way of braking faster, they'll consume this as a
performance benefit.

This is likely true.

But saying ABS does not provide braking distance benefits
(in general) is untrue, even if I agree with you that we
should be trying to stop drivers consuming all safety
benefits in the form of increased performance.

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On Tue, 22 Jun 2004 11:18:50 +0100, "Just zis Guy, you know?"
<[email hidden]> wrote (more or less):

Quoted message said:

Gawnsoft said:

Quoted message said:

In other words, yes and no, but for practical purposes
no, unless the wheels would be locking up. Which they
generally don't.

Quoted message said:

You don't drive in the wet much, do you Guy?

I don't drive much at all these days. And I don't generally
drive close enough to the car in front that I need to brake
sharply in the wet or in the dry.

...

True, but saying wheels "generally don't" lock up is all
very well. But in those circumstances, ABS wouldn't be used
in any event.

I thought we were discussing use of ABS?

Which, generally, only get used under emergency braking
conditions.

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On Tue, 22 Jun 2004 12:39:54 +0100, "Just zis Guy, you know?"
<[email hidden]> wrote (more or less):

Quoted message said:

Velvet said:

It's not just about driving too close to the car in
front, there's always the idiot that swerves into your
path as an oncoming, or the one that pulls out right in
front from the side junction *despite* the fact that you
saw him look at (or was it *through* you)...

Oh really, I didn't know that, only having had a driving
licence for 20 years...

Different premises. What ABS is designed to do is prevent
the wheels locking, allowing you to maintain control when
braking. As an aside it also helps to ensure that hammering
the brakes doesn't end up in a skid.

...

Original this was in reverse order.

ABS was to prevent skidding. It also allowed you to steer
throughout an emergency brake.

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On Tue, 22 Jun 2004 17:39:18 +0100, Gawnsoft
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

But Velvet's generalisation is more generaly true that your
generalisation, Guy.

Quoted message said:

You say Guy 'ABS is not there to shorten braking
distances'. In fact it does.

Actually we are both right. That's not what it's for, but as
a side effect it can.

Quoted message said:

Your main objection seems to be that if folk think of ABS
as a way of braking faster, they'll consume this as a
performance benefit.

They do indeed. It's like telling people a helmet will save
their life. It could conceivably happen, but that's not what
it's designed for and you shouldn't rely on it.

Guy
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88% of helmet statistics are made up, 65% of them at
Washington University

Just zis Guy said:

Unfamiliarity and the fact that greater concentration is
necessary. Nor is that a new thing - JS Dean commented on
in in 1946! The signs and markings were expunged pretty
much completely, as I recall; certainly centrelines and
give way markings, and in some cases they've tried
removing traffic lights as well.

So do you think the roads would be, overall, safer, if
all signs (say except direction signs) and lining schemes
were removed?

--
speedlimit.org.ukspeedlimit.org.ukOpen ↗
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On Tue, 22 Jun 2004 19:31:22 +0100, "PeterE"
<peter@xyz_ringtail.fsnet.co.uk> wrote in message
<[email hidden]>:

Quoted message said:

So do you think the roads would be, overall, safer, if
all signs (say except direction signs) and lining schemes
were removed?

Probably depends on the location. Some roads have been made
safer by doing just that. Certianly the experience where
roads have been treated with lots of paint and signage has
often been that drivers simply speed up and the crash rate
remains unchanged.

Guy
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88% of helmet statistics are made up, 65% of them at
Washington University

In "]news:[email hidden],
Velvet <[email hidden]> typed:

Quoted message said:

Just zis Guy, you know? wrote: It's not just about driving
too close to the car in front, there's always the idiot
that swerves into your path as an oncoming, or the one
that pulls out right in front from the side junction
*despite* the fact that you saw him look at (or was it
*through* you)...

Isn't that to say that otherwise you would have eased off
the accelerator when passing the oncoming car or the mouth
of the junction. That's certainly what my copy of the HMSO's
/Driving/ advises as best practice. In that case you may
well have swallowed or more than swallowed the benefit of
the ABS in the additional speed.

A

Just zis Guy said:

On Tue, 22 Jun 2004 19:31:22 +0100, "PeterE"
<peter@xyz_ringtail.fsnet.co.uk> wrote in message
<[email hidden]>:

Quoted message said:

So do you think the roads would be, overall, safer, if
all signs (say except direction signs) and lining schemes
were removed?

Probably depends on the location. Some roads have been
made safer by doing just that. Certianly the experience
where roads have been treated with lots of paint and
signage has often been that drivers simply speed up and
the crash rate remains unchanged.

Hmm, bit of a weasel answer, that one. I suspect when put on
the spot you'd find reasons for keeping most of the signs -
those round white ones with a red border and black numbers
on them in particular ;-)

--
speedlimit.org.ukspeedlimit.org.ukOpen ↗
"Banning things others enjoy is the only pleasure some people get."

Ambrose Nankivell said:

In "]news:[email hidden],
Velvet <[email hidden]> typed:

Quoted message said:

Just zis Guy, you know? wrote: It's not just about driving
too close to the car in front, there's always the idiot
that swerves into your path as an oncoming, or the one
that pulls out right in front from the side junction
*despite* the fact that you saw him look at (or was it
*through* you)...

Isn't that to say that otherwise you would have eased off
the accelerator when passing the oncoming car or the mouth
of the junction. That's certainly what my copy of the
HMSO's /Driving/ advises as best practice. In that case
you may well have swallowed or more than swallowed the
benefit of the ABS in the additional speed.

A

Um, no. Round here in the south east (london) if you did
that at every junction or oncoming car you'd be doing a
grand 0mph in very short order, unfortunately.

--

Velvet

PeterE said:

Quoted message said:

Quoted message said:

So do you think the roads would be, overall, safer, if
all signs (say except direction signs) and lining
schemes were removed?

Quoted message said:

Quoted message said:

Probably depends on the location. Some roads have been
made safer by doing just that. Certianly the experience
where roads have been treated with lots of paint and
signage has often been that drivers simply speed up and
the crash rate remains unchanged.

Quoted message said:

Hmm, bit of a weasel answer, that one. I suspect when put
on the spot you'd find reasons for keeping most of the
signs - those round white ones with a red border and black
numbers on them in particular ;-)

No, a straight answer. Speed limit signs are, of course, not
present in the first place in the places this has been
tried, being either restricted roads or NSL.

--
Guy
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"PeterE" <peter@xyz_ringtail.fsnet.co.uk> wrote in message
"]news:[email hidden]...

Quoted message said:

So do you think the roads would be, overall, safer, if all
signs (say except direction signs) and lining schemes were
removed?

and height restrictions, width restrictions, weight
restrictions, parking restrictions, level crossing warnings
and lights....

Nathaniel Porter said:

"Just zis Guy, you know?" <[email hidden]>
wrote in message
"]news:[email hidden]...

Quoted message said:

On Mon, 21 Jun 2004 22:25:28 +0100, "PeterE"
<peter@xyz_ringtail.fsnet.co.uk> wrote in message
<[email hidden]>:

Quoted message said:

> But is there a proven alternative to speed bumps,
> round or flat tops, and the raised platforms our
> Council are fitting at each minor road junction?

Quoted message said:

Yes. No speed humps or platforms.

Or paint or signage.

Quoted message said:

We can dream :-)

The problem is that the alternatives require sense. Councils
have more money than sense. So they choose to spend money
foolishly. To do otherwise would be illogical, Captain.

--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
["]http://www.dai.ed.ac.uk/homes/cam/]

On Wed, 23 Jun 2004 15:31:47 +0100, Clive <[email hidden]>
wrote (more or less):

Quoted message said:

In message <[email hidden]>, "Just zis Guy,
you know?" <[email hidden]> writes

Quoted message said:

It is a commonly held view, and it is responsible for
risk compensation behaviour which means that overall
what advantage there is is consumed as a performance
benefit. As ever.

This is like saying "replace the airbag with a six inch
steel spike." the driver will be much more careful, though
I not sure any safer.

Depend swhat you mean by 'safer'.

'Less likely to be involved in a fatality' is different from
'less likely to die him/herself'
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Clive said:

Quoted message said:

It is a commonly held view, and it is responsible for
risk compensation behaviour which means that overall
what advantage there is is consumed as a performance
benefit. As ever.

Quoted message said:

This is like saying "replace the airbag with a six inch
steel spike." the driver will be much more careful, though
I not sure any safer.

It's more like telling someone a helmet will Save
Their Life [tm]

--
Guy
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