Helicopter on A40 for collision within average speed cameras
Discussion
vonhosen said:
It's not about whether speed cameras save lives, it's about whether speed limits do.
I don't disagree, although I'd qualify that statement so it's about the levels at which the limits are set, rather than whether or not they existBut now all we need are the research findings which show that said speed limits do indeed have the desired effect.
In any case, if they don't think that it's about whether speed cameras save lives, then how come they keep on trying to push that point?
Edited by Pete317 on Sunday 29th November 13:46
Dave Finney said:
Devil2575 said:
Dave Finney said:
Devil2575 said:
Dave Finney said:
Independent reports, OTOH, have managed to produce results that do not contain any site-selection effects. They found that the entire KSI reduction was due to the effect of site-selection and that there was no KSI reduction after speed cameras were deployed.
Care to link to these reports?http://speedcamerareport.co.uk/08_mobile.htm
This was the second report to have fully excluded the effect of site-selection from the final results:
http://speedcamerareport.co.uk/09_fixed.htm
I found this report...
http://www.racfoundation.org/assets/rac_foundation...
In the first 3 NSCP reports, the authorities tried to claim that site selection had no effect at all but, in the 4th, they estimated that site selection might be a larger influence on KSI rates than all other factors combined.
What you've found is Professor Allsop's 2010 report for the RAC Foundation, which I think was the authorities 2nd attempt at estimating site selection effects (or RTM). You'll notice that the method used is in 2 parts, the 1st part could have been accurate but the actual SSP has since been found to be substantially longer than was assumed. [b]The 2nd part is a model that turns out to be incorrect for speed cameras.
As accuracy has increased, site selection has been found to have a greater influence than was first thought. When site selection was eventually measured, it was found to be responsible for the entire KSI reduction, with the speed cameras not demonstrated to have saved any lives, and not demonstrated to have prevented any serious injuries.[/b]
There is an easy solution: run speed cameras within simple scientific trials.
Devil2575 said:
Not trying to be funny, but do you have links to reports which aren't peppered with meaningless and/or nonsensical statements like, "These figures are broadly consistent with what one might expect to see", and "The laws of motion imply that lower speeds just before and at the instant of collision are associated with more time for the driver to take avoiding or mitigating action"Pete317 said:
Now that you've gotten that out of your system...
What do you want me to say?One report is written by a respected academic qualified in the subject matter and the other reports are written by someone who has set up a website.
Forgive me for giving more credence to one than the others.
Devil2575 said:
Pete317 said:
Now that you've gotten that out of your system...
What do you want me to say?One report is written by a respected academic qualified in the subject matter and the other reports are written by someone who has set up a website.
Forgive me for giving more credence to one than the others.
With such reports, what matters is not who wrote them but what they say, or, more to the point, what they actually show
And a respected academic should know better than to throw in a lot of irrelevancies and the like, which lend nothing of substance to the conclusions
Even worse is stuff like the unsupported psychobabble about drivers being incapable of judging the effects of speed - especially when it's totally irrelevant to the aims of the report.
Such stuff has no place in a supposedly objective report, and leaves one with the impression that either it was an attempt to bolster weak findings, or that the report was 'made to order'.
As for the other reports, I hadn't even read them, let alone given them any credence. I had little reason to, not least of all because I'm really not interested in entering into someone else's battles.
Edited by Pete317 on Monday 30th November 21:20
Devil2575 said:
Pete317 said:
Now that you've gotten that out of your system...
What do you want me to say?One report is written by a respected academic qualified in the subject matter and the other reports are written by someone who has set up a website.
Forgive me for giving more credence to one than the others.
1) believe what the authorities tell us
2) examine the evidence
As we rarely have the time to take option 2, we usually take option 1. The hope is that we would have reached the same conclusion from option 2 anyway but, as numerous events and scandals demonstrate, this is not always the case.
In the case of speed cameras:
2008: I developed and published my "Four Time Period" method
2010: Professor Allsop published his 1st report for the RAC Foundation
2012: I published the 1st report using my "Four Time Period" method (http://speedcamerareport.co.uk/08_mobile.htm)
2013: Professor Allsop recommended that researchers use my "Four Time Period" method
2013: The DfT and the RAC Foundation endorse my "Four Time Period" method
So there is much more agreement than some might suggest!
Pete317 said:
With such reports, what matters is not who wrote them but what they say, or, more to the point, what they actually show
If only life were that simple.That only works if you have sufficient background and understanding to interpret what they show.
In this case that may not be too difficult but I can think of many examples where it would be impossible for a layperson to make any sense of what they are reading.
Let me put it another way, if you're ill you go to a doctor because of who they are not based on what they say. Or do you think that the best approach is to see what people have written on the internet about the symptoms you are experiencing and decide a course of action based on your understanding?
When I get a chance I'll read the reports and let you know what I think. I currently don't have time.
Devil2575 said:
Pete317 said:
With such reports, what matters is not who wrote them but what they say, or, more to the point, what they actually show
If only life were that simple.That only works if you have sufficient background and understanding to interpret what they show.
In this case that may not be too difficult but I can think of many examples where it would be impossible for a layperson to make any sense of what they are reading.
Let me put it another way, if you're ill you go to a doctor because of who they are not based on what they say. Or do you think that the best approach is to see what people have written on the internet about the symptoms you are experiencing and decide a course of action based on your understanding?
When I get a chance I'll read the reports and let you know what I think. I currently don't have time.
But we don't live in the ideal world - so even recognised experts sometimes get things badly wrong, regardless of how well-respected or well-intentioned they are.
So your layperson would really have no way of knowing whether what they're reading is correct, and although the standing of the author might serve as a rough guide to the correctness and/or accuracy, it's by no means infallible.
On the plus side however, the uninformed layperson is seldom, if ever, called on to make far-reaching decisions based on what they understand from the reports.
It's the politicians that worry me in that respect - they know little to nothing, yet make far-reaching decisions which may be based on little more than the fact that they like the author and/or what they're saying.
So when I see a report which is peppered with irrelevancies and the like, experience has taught me to be somewhat cynical wrt its findings.
Edited by Pete317 on Tuesday 1st December 13:16
Pete317 said:
So when I see a report which is peppered with irrelevancies and the like, experience has taught me to be somewhat cynical wrt its findings.
Perhaps you should read it first before drawing conclusions. Being skeptical is good, being cynical is not.Edited by Pete317 on Tuesday 1st December 13:16
Also personal experience leads many of us down blind alleys, as our experiences are frequenty coloured by our prejudices.
Devil2575 said:
Being skeptical is good, being cynical is not.
No, I meant cynical, and it's not as if I get any pleasure from being cynical.I'm pretty sceptical at the best of times, but throwing a lot of irrelevancies and the like into a report is almost always either an attempt to detract from weak findings, or to make the report seem like it's saying something which it doesn't, neither of which can be said to be borne of particularly honest motives.
If I see something in such a report which makes me change my mind about it, then I do.
Edited by Pete317 on Tuesday 1st December 18:07
Pete317 said:
Devil2575 said:
Being skeptical is good, being cynical is not.
No, I meant cynical, and it's not as if I get any pleasure from being cynical.I'm pretty sceptical at the best of times, but throwing a lot of irrelevancies and the like into a report is almost always either an attempt to detract from weak findings, or to make the report seem like it's saying something which it doesn't, neither of which can be said to be borne of particularly honest motives.
If I see something in such a report which makes me change my mind about it, then I do.
Edited by Pete317 on Tuesday 1st December 18:07
tapereel said:
A lot of the items you term as "irrelevancies" are, in my opinion very relevant. In my opinion that suggests you either haven't read it, haven't understood it or are not competent to interpret it.
You're welcome to your opinions.If you think that something is relevant, then identify it and state why you think it's relevant, then perhaps we can discuss it.
cheesesliceking said:
Dave Finney said:
Some colleagues have said that, in decades travelling the A40, they have never known the A40 closed due to a collision.
It was closed due to the air ambulance landing... not the collision itself and not due to the average speed cameras.Your lunatic is showing btw.
cheesesliceking said:
Dave Finney said:
Some colleagues have said that, in decades travelling the A40, they have never known the A40 closed due to a collision.
It was closed due to the air ambulance landing... not the collision itself and not due to the average speed cameras.Your lunatic is showing btw.
If you wish to have people take your reports seriously you should really refrain from making comments that clearly show your bias and the effect it has on your judgement.
Is it possible to have an intelligent, grown-up debate about speed cameras? I am determined to believe that it is.
What I actually wrote was: "Some colleagues have said that, in decades travelling the A40, they have never known the A40 closed due to a collision, others have said they've experienced closure due to a collision once before. No-one has heard of the air ambulance landing on the A40 before."
I have campaigned for speed cameras. Some years ago when it looked as though many speed cameras might be removed, I campaigned for as many as possible to remain within a scientific trial. When TfL decided to trial average speed cameras, I campaigned for their average speed cameras to be installed within a scientific trial. Let's use speed cameras, but we need to know what effect they're having and, since the authorities have been unable to determine their effect, this must be done within scientific trials.
When we have speed cameras deployed within scientific trials, we will finally have the evidence upon which to base a valid judgement.
http://speedcamerareport.co.uk/02_scientific_trial...
What I actually wrote was: "Some colleagues have said that, in decades travelling the A40, they have never known the A40 closed due to a collision, others have said they've experienced closure due to a collision once before. No-one has heard of the air ambulance landing on the A40 before."
I have campaigned for speed cameras. Some years ago when it looked as though many speed cameras might be removed, I campaigned for as many as possible to remain within a scientific trial. When TfL decided to trial average speed cameras, I campaigned for their average speed cameras to be installed within a scientific trial. Let's use speed cameras, but we need to know what effect they're having and, since the authorities have been unable to determine their effect, this must be done within scientific trials.
When we have speed cameras deployed within scientific trials, we will finally have the evidence upon which to base a valid judgement.
http://speedcamerareport.co.uk/02_scientific_trial...
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