Cycle helmets - major study

[Paul Smith]

On Sat, 26 Apr 2003 17:50:32 +0100, "Tony Raven" <[email protected]> wrote:

>Gonzalez <[email protected]> wrote:

>> Who would you rather travel as a passenger with: a tired driver hacking down the motorway at 95
>> mph, or a tired driver cruising down the motorway at 65 mph.

>The former because the journey will be over with quicker. A crash is going to hurt some at either
>speed so I'll go for the shorter exposure time ;-)

That's one factor... Which driver is more likely to fall asleep per unit time?
--
Paul Smith Scotland, UK http://www.safespeed.org.uk please remove "XYZ" to reply by email speed
cameras cost lives

 

[Just Zis Guy]

On Sat, 26 Apr 2003 10:26:45 +0100, Mohammed Saeed Al-Smith <[email protected]> wrote:

>The best place to look for elevated inattention is where we've forced a driver to travel at a speed
>significantly slower than the one he judges to be safe. He's bored and disinterested in his task.

Ah, yes, the driver decides that it's definitely safe to go much faster than he's allowed so the
driver decides he need not pay attention and kills someone. The hallmark of good and competent
drivers everywhere, obviously. The observed fact that most drivers overestimate their own skills is
not, of course, to be taken into account.

Sadly this kind of crass idiocy is now enshrined in road "safety" policy to the extent that the
Government's official remedy for SMIDSYs is to encourage their victims to drive more carefully.

Frankly anybody commuting by car is bored and disinterested most of the time anyway. I can't think
of anybody I know who commutes by car who regards it as anything other than a monumental pain in the
****. They should try cycling - much more stimulating.

Guy
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[Just Zis Guy]

On Sat, 26 Apr 2003 17:38:35 +0100, Gonzalez <[email protected]> wrote:

>I have frequently driven at 30 in lane 3 of a motorway, especially the M6 around Birmingham.

You lucky *******! I can't remember the last time I saw it move that fast!

Guy
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[Just Zis Guy]

On Sat, 26 Apr 2003 18:31:12 +0100, Mohammed Saeed Al-Smith <[email protected]> wrote:

>It's extremely likely that the tired 65mph driver could improve his safety and alertness by
>speeding up to 95mph, as long as to do so was within normal safety margins (i.e. vision, traffic,
>capability etc).

Not half as much as he could improve his safety (and that of all those around him) by pulling off at
the next opportunity and sleeping for 15 minutes, rather than ploughing on and hoping he didn't
become another Gary Hart.

And any driving instructor, advanced or otherwise, who doesn't agree with this is incompetent.

Guy
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[Paul Smith]

On Sat, 26 Apr 2003 19:59:18 +0100, "Just zis Guy, you know?" <[email protected]> wrote:

>>It's extremely likely that the tired 65mph driver could improve his safety and alertness by
>>speeding up to 95mph, as long as to do so was within normal safety margins (i.e. vision, traffic,
>>capability etc).

>Not half as much as he could improve his safety (and that of all those around him) by pulling off
>at the next opportunity and sleeping for 15 minutes, rather than ploughing on and hoping he didn't
>become another Gary Hart.

Tiredness is somewhat relative isn't it? It's perfectly OK to drive when tired, but we all must stop
before we are too tired.

>And any driving instructor, advanced or otherwise, who doesn't agree with this is incompetent.

I couldn't agree more except that tiredness isn't absolute.
--
Paul Smith Scotland, UK http://www.safespeed.org.uk please remove "XYZ" to reply by email speed
cameras cost lives

 

[Paul Smith]

On Sat, 26 Apr 2003 19:30:11 +0100, "Just zis Guy, you know?" <[email protected]> wrote:

>>Unnecessarily slow speeds become dangerous when they are soporific or when the means of reducing
>>speed distracts drivers or otherwise reduces their concentration or distorts their priorities.

>Luckily, 30mph (and lower) speed limits around towns are completely necessary, and amply justified
>by an examination of the probabilities of death when pedestrians are hit at various speeds. So
>that's all right then.

30mph speed limits are amply justified on some roads, especially town roads.

But that doesn't tell us that lowering speed limits or increasing enforcement will make the
roads safer.

As far as pedestrian impacts are concerned it's quite clear from an examination of the facts that
impacts at free travelling speeds are rare, and we should be looking at the factors which already
mitigate 99%+ of such impacts and their severity to find further improvements.
--
Paul Smith Scotland, UK http://www.safespeed.org.uk please remove "XYZ" to reply by email speed
cameras cost lives

 

[Robert Goodman]

> >My experience playing rugby tells me that as soon as I start
breathing
> >hard, my mental capacity diminishes.

> You are confusing two effects: mental capacity dimishes *as you start playing rugby* <gd&r>

> Guy
> ===
Oh. I thought you were going to say mental capacity must be diminished BEFORE one decides to
play rugby.

 

[Gonzalez]

Paul Smith wrote:

>The Italian Government agrees and has recently raised the motorway speed limit "to improve
>alertness".

So all those overhead gantry signs have got it wrong...

Instead of saying, "don't drive tired, take a break", they should say, "Feeling tired? Then
speed up!"
--
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[Paul Smith]

On Sat, 26 Apr 2003 21:42:37 +0100, Gonzalez <[email protected]> wrote:

>>The Italian Government agrees and has recently raised the motorway speed limit "to improve
>>alertness".

>So all those overhead gantry signs have got it wrong...

>Instead of saying, "don't drive tired, take a break", they should say, "Feeling tired? Then
>speed up!"

30% of accidents on some UK motorways are believed to be sleep related. I would have thought that a
proper basket of measures would be appropriate. Nevertheless I don't think it's sound advice to
speed up if you feel tired.

On the other hand, driving at a decent speed suitable for the conditions may delay the onset of
significant tiredness. This could well be a valuable lifesaver.
--
Paul Smith Scotland, UK http://www.safespeed.org.uk please remove "XYZ" to reply by email speed
cameras cost lives

 

[Graeme]

Paul Smith <[email protected]> wrote in news:[email protected]:

> On the other hand, driving at a decent speed suitable for the conditions may delay the onset of
> significant tiredness. This could well be a valuable lifesaver.

We've heard some real bull **** from you so many times, but this takes top marks! Do us all a
favour, when you're next due to fall asleep, go out an get some hard evidence for us. Drive at 90mph
along a deserted road and see if it wakes you up. You might get woken up by the sudden adrenaline
rush just as you realise you're headed for a tree, but you'll at least have the satisfaction of
knowing you're right.

 

[Paul Smith]

On Sun, 27 Apr 2003 09:55:11 -0000, Graeme <[email protected]> wrote:

>Paul Smith <[email protected]> wrote in news:[email protected]:

>> On the other hand, driving at a decent speed suitable for the conditions may delay the onset of
>> significant tiredness. This could well be a valuable lifesaver.

>We've heard some real bull **** from you so many times, but this takes top marks! Do us all a
>favour, when you're next due to fall asleep, go out an get some hard evidence for us. Drive at
>90mph along a deserted road and see if it wakes you up. You might get woken up by the sudden
>adrenaline rush just as you realise you're headed for a tree, but you'll at least have the
>satisfaction of knowing you're right.

There's no need to attack me because you don't have a clue.
--
Paul Smith Scotland, UK http://www.safespeed.org.uk please remove "XYZ" to reply by email speed
cameras cost lives

 

[Tony Raven]

Graeme <[email protected]> wrote:
>
> We've heard some real bull **** from you so many times, but this takes top marks! Do us all a
> favour, when you're next due to fall asleep, go out an get some hard evidence for us. Drive at
> 90mph along a deserted road and see if it wakes you up. You might get woken up by the sudden
> adrenaline rush just as you realise you're headed for a tree, but you'll at least have the
> satisfaction of knowing you're right.

I know its not the acceptable thing to agree with anything Paul says in this newsgroup but I'm going
to stick my neck out. I used to travel a lot internationally so two to four times a month I was
dealing with significant jet lag from 6-12hour time shifts. I found the best way of dealing with it
was to keep myself busy during the normal day wherever I was. As long as I was mentally occupied I
could function quite normally and wouldn't feel tired although my judgement and attention span was
not up to scratch for which I made a concious allowance. The moment there was a lull in proceedings
the tiredness would catch up with me and I would struggle not to take a nap.

I am absolutely certain from personal experience that mental concentration can ward off the effects
of tiredness very effectively and its backed up by research. NASA have a team (the Fatigue
Countermeasures Group or "Z team" ) who specifically study this particularly for flight operations.
An interesting quote from the US Navy Flight Surgeons Manual chapter on fatigue says "Interesting
tasks with relatively simple motor skills are resistant for periods as long as 60 hours, but routine
monotonous tasks show a rapid decrement after 18 hours without sleep."

So while I don't agree with driving tired, it is much better if you are doing a challenging task for
a shorter time than a boring one for the same time or longer if you are going to be doing it.

Incidentally there is a factor in the airline industry called "sleep inertia" which is the first 30
mins after being woken are equally risky while you transition from sleep to fully awake. If you are
going to nap keep it short (<45 mins) because once you get into deep sleep, sleep inertia will add
to your problems for 30 mins after you wake. I always allow a good 30 mins in the morning between
getting up and driving.

Tony

 

[James Hodson]

On Fri, 25 Apr 2003 15:41:04 -0400, "Robert Goodman" <[email protected]> wrote:

>The last time I played I was propping and in the 2nd half the ref didn't like the way we were
>forming scrums, so he said he'd have us touch & engage on his call. I said, yeah, sure, and then as
>we crouched he said, "Touch" maybe 3 times before I realized, "Dummy, he's talking to YOU!" I was
>just staring at my immediate opponent waiting for something to happen. I'm sure that wouldn't've
>happened if I had a cool head.
>

I'm trying to keep an open mind about forwards, especially front row ones. ;-))

James

--
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[James Hodson]

On Sat, 26 Apr 2003 16:24:25 -0400, "Robert Goodman" <[email protected]> wrote:

>Oh. I thought you were going to say mental capacity must be diminished BEFORE one decides to
>play rugby.
>

Beat me to it, Robert.

James

--
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[James Hodson]

On Fri, 25 Apr 2003 15:41:04 -0400, "Robert Goodman" <[email protected]> wrote:

>Well, yeah, that's probably because you were good!
>

Not particularly. However, I also used to ski and, thinking about, my brain did used to feel the way
you describe when you were playing in your rugby matches.

FWIW, I was a far better skier than I ever was a rugby player.

James

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[Graeme]

Paul Smith <[email protected]> wrote in news:[email protected]:
> There's no need to attack me because you don't have a clue.

I'm attacking you because a) for some reason my killfile seems to have let you slip past and b)
whilst some people may find your contributions mildly entertaining I am one of the many who find
them tedious, generally based on dubious claims and almost entirely unrelated to the subject of
this newsgroup, i.e. cycling. However the main reason is c) you come across as an irritating
little pillock who doesn't have the wit to be able to contribute on anything other than his own
pet subject.

Back in the killfile you go, hopefully you'll stay there and hopefully you won't provoke others into
trying to talk some sense into you. There seems little point.

Graeme

 

[Just Zis Guy]

On Sun, 27 Apr 2003 12:02:00 +0100, Paul Smith <[email protected]> wrote:

>There's no need to attack me because you don't have a clue.

I think they are attacking you because *you* don't have a clue. Subtle difference, I know, but...

Guy
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[Just Zis Guy]

On Sat, 26 Apr 2003 20:13:02 +0100, Paul Smith <[email protected]> wrote:

>>>It's extremely likely that the tired 65mph driver could improve his safety and alertness by
>>>speeding up to 95mph, as long as to do so was within normal safety margins (i.e. vision, traffic,
>>>capability etc).

>>Not half as much as he could improve his safety (and that of all those around him) by pulling off
>>at the next opportunity and sleeping for 15 minutes, rather than ploughing on and hoping he didn't
>>become another Gary Hart.

>Tiredness is somewhat relative isn't it? It's perfectly OK to drive when tired, but we all must
>stop before we are too tired.

Tiredness sufficient to make it difficult to concentrate when driving legally is excessive and
should be dealt with by stopping for a rest of some sort. That much is an absolute.

Guy
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[Just Zis Guy]

On Sat, 26 Apr 2003 20:23:38 +0100, Paul Smith <[email protected]> wrote:

>30mph speed limits are amply justified on some roads, especially town roads. But that doesn't tell
>us that lowering speed limits or increasing enforcement will make the roads safer.

No, the figures from areas where average speeds have been reduced do that perfectly well.

>As far as pedestrian impacts are concerned it's quite clear from an examination of the facts that
>impacts at free travelling speeds are rare,

Did you learn nothing from the argument about the Joksch equations? Energy is proportional to speed
squared, so the ability to stop, or at least to reduce speed sufficiently to avoid fatality, is
significantly affected by the initial speed.

>and we should be looking at the factors which already mitigate 99%+ of such impacts and their
>severity to find further improvements.

Instead of apologising for speeders and the terminally clusless, and forcing their victims to take
extra measures to protect themselves. Quite.

Guy
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[Chris Malcolm]

Paul Smith <[email protected]> writes:

>Unnecessarily slow speeds become dangerous when they are soporific

Nothing is soporific if one is not tired. Therefore your statement should be translated into "If you
are tired then the excitement of travelling fast may keep you from falling asleep."

--
Chris Malcolm [email protected] +44 (0)131 650 3085 School of Artificial Intelligence, Division of
Informatics Edinburgh University, 5 Forrest Hill, Edinburgh, EH1 2QL, UK
[http://www.dai.ed.ac.uk/daidb/people/homes/cam/ ] DoD #205