Everything we know about traffic-calming is wrong
 

On Mon, 21 Jun 2004 09:29:58 +0100, "Just zis Guy, you know?"
wrote:

On Sun, 20 Jun 2004 22:37:33 GMT, Velvet
wrote in message :

So it's not quite as clear cut that all the extra safety stuff makes
people drive less carefully :-)

It is, though. The taxi driver ABS trial was a near-perfect
double-blind study and it showed that those driving ABS equipped cars
accelerated harder, braked harder, drove faster and followed closer.

What particular form of psychic capability was reckoned to account for this,
then ? As soon as any driver realised his vehicle had ABS, the trial failed
the double-blind test, which demands that those taking part and the
observers are both ignorant of the conditions.

(I don't have any problem with trials that show that drivers fully aware of
such features may "risk compensate" for them. But claiming to have
double-blind trial results smacks of very dodgy science.)

--
He said: Smile, things could be worse! I did! They were!

Mail john rather than nospam...

Everything we know about traffic-calming is wrong
 

On Mon, 21 Jun 2004 10:53:47 +0100, John Laird
wrote in message
:


It is, though. The taxi driver ABS trial was a near-perfect
double-blind study and it showed that those driving ABS equipped cars
accelerated harder, braked harder, drove faster and followed closer.

What particular form of psychic capability was reckoned to account for this,
then ? As soon as any driver realised his vehicle had ABS, the trial failed
the double-blind test, which demands that those taking part and the
observers are both ignorant of the conditions.

The condition being tested was "driver knowingly driving ABS equipped
car". The drivers did not know which cars were fitted with measuring
devices, and the observers did not know which measuring devices
werefitted to cars with ABS.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

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

Everything we know about traffic-calming is wrong
 

On Mon, 21 Jun 2004 10:42:13 +0100, "Grant Mason"
wrote in message :

Er, actually ABS doesn't really affect stopping distances.

Yes it does.
http://www-nrd.nhtsa.dot.gov/vrtc/ca...99-01-1287.pdf
"For most stopping maneuvers, made on most test surfaces, ABS-assisted panic
stops were found to be shorter than those made with best effort or full
pedal applications with the ABS disabled"

Because people don't know how to brake. But the statement was overly
simplistic, of course.

ABS does not increase the power of the brakes, and does not increase
the coefficient of friction. All it does is make it less likely that
the driver will lock the wheels.

Which, to a first approximation, is the same thing as "doesn't stop
you quicker" - letting people believe that ABS stops you quicker is
Not Smart in my view because in the end it doesn't affect the two main
factors in stopping you.

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.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

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

Everything we know about traffic-calming is wrong
 

"Richard J." wrote in news:b5yBc.1632
:

Overall, driving with belts is
safer than it used to be, i.e. it kills fewer people.


That's not what the research that the government did showed. Then again,
they don't tend to shout about that research too much for obvious reasons.

Graeme

Everything we know about traffic-calming is wrong
 

On Sun, 20 Jun 2004 at 23:15:30, "Just zis Guy, you know?"
wrote:

On the other hand, they drive less carefully when protected by
airbags, abs and seatbelts.

When I tried, abortively, to learn to drive many years ago now, my
father commented that one should always remember that *every* other car
on the road was driven by a murderer. A lesson which I passed on to my
daughter when she learnt to drive.
--
Annabel Smyth
http://www.amsmyth.demon.co.uk/index.html
Website updated 6 June 2004

Everything we know about traffic-calming is wrong
 

On Mon, 21 Jun 2004 10:06:34 GMT, Graeme
wrote in message
:

That's not what the research that the government did showed. Then again,
they don't tend to shout about that research too much for obvious reasons.

Quite. You'll find the Isles Report in a locked filing cabinet in a
disused lavatory with a sign on the door saying "beware of the
leopard" - you'll need a ladder and a flashlight thobut ;-)

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

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

Everything we know about traffic-calming is wrong
 

On Mon, 21 Jun 2004 11:01:08 +0100, "Just zis Guy, you know?"
wrote:

On Mon, 21 Jun 2004 10:53:47 +0100, John Laird
wrote in message
:


It is, though. The taxi driver ABS trial was a near-perfect
double-blind study and it showed that those driving ABS equipped cars
accelerated harder, braked harder, drove faster and followed closer.

What particular form of psychic capability was reckoned to account for this,
then ? As soon as any driver realised his vehicle had ABS, the trial failed
the double-blind test, which demands that those taking part and the
observers are both ignorant of the conditions.

The condition being tested was "driver knowingly driving ABS equipped
car". The drivers did not know which cars were fitted with measuring
devices, and the observers did not know which measuring devices
werefitted to cars with ABS.

That makes more sense, thanks. Of course, testing taxi drivers is highly
dubious in itself ;-)

--
Just a fake guitar player in the Monkees of life.

Mail john rather than nospam...

Everything we know about traffic-calming is wrong
 

"Just zis Guy, you know?" wrote in
:

Quite. You'll find the Isles Report in a locked filing cabinet in a
disused lavatory with a sign on the door saying "beware of the
leopard" - you'll need a ladder and a flashlight thobut ;-)


For some reason the first thought that popped into my head after reading
that was "Hmm... must do my tax return." Now if anyone can explain the
thought process behind that I would be very grateful.

Graeme

Everything we know about traffic-calming is wrong
 

On Mon, 21 Jun 2004 09:43:35 GMT someone who may be "Richard J."
wrote this:-

My point was
that before seat belts were introduced, there were very many disastrous
accidents because many people *didn't* drive safely enough to avoid
being thrown through the windscreen. Overall, driving with belts is
safer than it used to be, i.e. it kills fewer people.

In theory you are correct.

However, practice is rather different to theory. Of course the
people not being killed as much are those inside cars, while those
being killed more are outside cars. If one has a road "safety"
policy that is only concerned with the former then one can present
this as a "success". See the Isles Report and the Durbin/Harvey
Report.


--
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.

Everything we know about traffic-calming is wrong
 

"Just zis Guy, you know?" wrote in
:

You'll find the Isles Report in a locked filing cabinet in a
disused lavatory with a sign on the door saying "beware of the
leopard" - you'll need a ladder and a flashlight thobut ;-)


And on a related subject
http://www.bbc.co.uk/radio4/hitchhikers/index_new.shtml

Bloody excellent! Now if only I can sort out timed recordings so I don't
have to get up at 2am!
:-)
:-0

And I can imagine Guy's reaction :{)


Graeme