Safe Speed Forums

Really? It looks pretty normal to me.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

I don't think we're talking "counter-intuitive" here. I think we're talking about: "the moon is made of green cheese"!

I'm a very evidence based thinker, but there's a bloody limit!

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

You find the 'agree/disagree' test so unbelievable you wouldn't accept it even on evidence.

By the same token if I were to say 'I've got a unicorn in my garden' you (correctly) would not believe it even if I supplied photographs.

But in the Unicorn case, everyone would be in agreement; in this case, many would take the opposite view, that the test is axiomatically true, not false. One could probably largely predict views depending on whether they were keen motorist/rambler, technocrat/greeen, engineer/poet etc. So the question of whether you or I might think the finding incredible is irrelevant, it's just prejudice.

The question is: is it true?

Anyone know how to contact the authors or current owners of Roadcraft to find out what they say?

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I pay tax on all my cars

I don't accept your examples. This is a claim more along the lines of "Brighter light bulbs use more voltage". Anyone who knows about light bulbs and electrical power could dismiss it immediately and with certainty, while a lay person may well be nodding.



Start with the Police Foundation:
http://www.police-foundation.org.uk
I think they hold the copyright.

If you have the time and the inclination, I'd be very pleased indeed to examine the basis of page 11.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

If you said to me, "Brighter light bulbs use more voltage", I would say "Sure!". But if you then said "Wanna bet?" I would turn it down, and so would anyone who's ever been caught by counter-intuitive stuff before. But on a unicorn in your garden I'd bet all I could beg, borrow or steal.

But you and I will clearly never agree on this issue, so I'll say no more on it. I've done so; I don't expect to get much of a reaction, since if this raw data were widely available I don't think this discussion would be taking place; the matter would be settled, one way or another.

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I pay tax on all my cars

Roy, I'm disappointed and a little concerned that we've ended up in this position, especially since you are clearly an intelligent new user.

I don't think you'll find another example anywhere in the forums or the web site.

I don't believe it's right to dismiss claims without evidence, but there's no evidence to fit this particular set of claims unless your contact reveals the original report.

I do have a logical dismissal for you which I now realise I've been running mentally without getting around to expressing it even to myself.

Note the responses here to the page from a range of well trained and crash free drivers. We know that highly trained drivers have a low crash rate and we know that at least some well trained drivers disagree with the claims.

I also happen to know that HPC trained drivers are running at over 500,000 miles per crash involvement while the national average is about 80,000 miles.

The claims could possibly be true within a small population of inexperienced drivers, where the answers turn out to be a proxy measure for caution. Trained drivers will obviously know better and not require proxy measures of caution.

Let's hope you find the original so we can get it cleared up properly.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Of course, if you consider a 12V 5W bulb, and a 240V 100W bulb, you could "prove" that higher voltage bulbs are brighter couldn't you?

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CSCP Latin for beginners...
Ticketo ergo sum : I scam therefore I am!

The claim is: "drivers who tend to disagree [test score of more than 21] turn out to have approximately five times the accident risk of those who agree". Taken literally, I'd accept the claim is probably true, on the grounds that if not true, it must have been falsified (which I think is less likely than accepting the truth of the claim).

The logical non-sequitur, implied by the way the claim is presented, is that any individual driver who "tends to disagree" has a higher accident risk than one who agrees. That is, as Paul said, patent nonsense.

The question is whether the raw statistical result, in itself, can support a relevant and useful conclusion. I'd say not. In any event, a statistical result presented without a conclusion is meaningless. The fact it's been presented in the way it has suggests attempted 'spin' or sophistry.

If we assume that only 10% of drivers would tend to agree (a total guess on my part), then presumably a statistical study, conducted over a time frame of one year, then out of a sample size of 10 000 representative drivers, there would be 28 crashes among the lot who do agree (using that you have an accident every 7 years roughly, therefore the 10% have one every 35 years roughly)... it doesn't seem very plausible, really.

I'm sure there are all sorts of silly correlations like this...

An interesting google search:

http://www.google.com/search?q=epidemio ... 8&oe=utf-8

Is it possible that the "tend to disagree" group might include both bad and safe drivers, and that's what skewing things? What I'm thinking about is that we know the most accident prone group by speed is the fastest 10%, and the safest is the next 10% down. But drivers from both groups would probably disagree overall.

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Make everything as simple as possible, but not simpler - Einstein

OK, I'm new here; I'll have another go. You said Roadcraft page 11 is clearly piffle - it's so obvious to me that it's piffle that I feel no need to verify the fact. If a study was done that purports to justify the page, then that study is obviously piffle too. If you stand by this then there's no point in continuing. There is only one claim. There will still be normal distribtution curve amongst highly trained drivers, shifted to the 'good' end. It would be necessary to survey these drivers also to find out whether attitude reflects accident rate in the same way. Or a large population of experienced drivers. Only the data will tell us.

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I pay tax on all my cars

Correct.

A smoker is (say) five times more likely to get lung cancer than a non-smoker; but you cannot point at any individual and say 'You'll get cancer'.

The claim says that a driver who 'tends to disagree' is more likely to have a higher accident risk. But no individual can be said to have such risk unless it can be shown that sharing those attitudes is itself the risk factor, which as you say has not been shown. (And not forgetting that the claim itself is unverified since we haven't got the data).

In the same way part of the smoking lobby argued for years that smoking was an indicator not a cause. And again in the same way more study is needed on attitudes. BTW and FWIW I'm not assuming the conclusion will be the same as with the smoking example, either.

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I pay tax on all my cars

According to recent reaserch smokers stand a 50% chance death from a smoking related illness.

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Speed camera policy Kills

To be clear; I made the number up just for the purposes of the argument. I gave up 24 years ago...

My request for info, BTW, is with the Foundation. Very helpful and pleasant, so far.

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I pay tax on all my cars

Good for you. I watched my father die of lung cancer 8 years ago. The crazy thing his father died of Pneumonia after years of bronchitis. He had is last cigarette on the day he died... Just goes to show, one generation does not learn from the previous.

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Speed camera policy Kills

My Dad died of lung cancer in 1981, six weeks from at work to box, age 57; his Dad died of smoking-induced gangrene when I was a little lad. Giving up was without doubt the hardest thing I ever did, taking it up at 16 the easiest and stupidest. And we wonder why people do mad things in cars?

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I pay tax on all my cars