hjeg2 wrote:
I didn't say that they were, but they are much better than nothing.
smeggy wrote:
Posted: Mon Dec 10, 2007 9:02 am
Please explain why you believe that to be.
hjeg2 wrote:
Posted: Mon Dec 10, 2007 7:40 pm
… I have seen figures that show that RTTM isn't the case; it's somewhere between that and the original DfT figures. In other words, speed cameras do have an effect.
[Then I mentioned ‘bias on selection’ where I thought that you meant something else.]
hjeg2 wrote:
A good example of where in my opinion they are much better than nothing is the A3 which is a three-laned road in west London. It used to have a 70 limit but now has a 50 limit, backed up by fairly frequent speed cameras. You used to get quite a lot of KSIs on it.
As we now know, the figures that I was talking about were the ones in George Monbiot’s article. The “original DfT figure” was something like a fall of 35% in KSIs attributed to speed cameras. When talking about RTTM like this there is/was an implication, even if you didn’t mean it, that RTTM is the sole cause of this fall – this is why I said above that “RTTM isn’t the case”.
Ah, now continuing down this thread I come on to the first of Robin’s posts. Well, well, well, it does seem, everyone (but especially Bombus, Smeggy and Robin), that it was Robin to start the pointless posts. I expect that Bombus and Smeggy will wish to criticise him for doing so, right?
Here are some of the points (or ‘points’ if you prefer) that I asked him which he then dodged:
hjeg2 wrote:
1. Oh right, so it's okay for you to make random 'points' which have no bearing whatsoever on the topic being discussed, but it's not okay for me to do the same?
2. What bearing does the following have then?
"Didn't take long to resume cutting up posts and answering points in isolation, and with no meaning, did it?"
3. And why did you say this:
"So where are these figures that debunk RTTM?" when I had already said this: "I'm afraid I can't remember where they were from"
4. And why bother saying this:
"The reason your avenue of debate has become vapid is that your only rebuttal is "some stats you saw, that were recent, but you can't remember where"." Who said it was meant to be a rebuttal?
5. Why say this:
"Physician..." What has that got to do with road safety?
6. Why say this:
"....and another!!"
7. And finally (I think), why put the "2" in hjeg2 in bold? You did it, not me, and now I'm just asking why.
It’s no good just saying that the above is “arguing about arguing” when it was Robin who came out with the comments that I am merely responding to.
Here are some points of Robin’s which I always intended to come back to, just as soon as I could get past the irrelevant rubbish that he comes out with:
Robin wrote:
There is plenty to read about RTTM on this site, if you venture outside the forum, and its a very simple concept to understand: If a road is accident free for a significant period, and then in one year there is a single incident in which 4 people, in the same vehicle, die, then siting a camera there does not mean that the following year's lack of fatalities is due in any part to the presence of the camera. Given that this is exactly how speed cameras have been sited, its not too hard to see that it must apply! The DfT's own report contained an acceptance of RTTM, albeit hidden in an annex, and there have been other, independent, reports pointing to it's significance.
No-one is arguing that RTTM doesn’t exist. Coming out with the above just shows how Robin is either confused or is, as usual, trying to engineer an argument with me. The point is whether RTTM is responsible just by itself for the reduction of collisions after a speed camera has been installed. [Have patience; I shall come back to this.]
Robin wrote:
More Police Officers - Speed cameras are not the only ill effect of current policy, the targets imposed on the police service also play a large part. The current administration is obsessed with measurement, even if the things they can measure are not really that important. Thus a speeding ticket issued counts as a crime detected and solved, a double tick.
This is another paragraph by Robin which only has a passing reference to the actual issues at hand. Yes, the targets, at least as they are now, are wrong. And the thing is, according to an article in The Times, is that there aren’t targets for motoring offences! This is why I say, and the police say, that even if we got rid of speed cameras we still wouldn’t get any more police on the roads.
smeggy wrote:
Posted: Wed Dec 12, 2007 2:19 pm
I presume you agree that I did not “clearly wanted to talk about stats”.
No because you said:
smeggy wrote:
Why should a lack of peer review prevent you from ‘arguing statistics’? If that's the case why are you here posting on this forum?
In other words if I wasn’t willing to argue statistics then I shouldn’t be on this forum – I took that, perhaps wrongly, to mean that you wanted to talk about stats.
As for the issue of peer review, I think we should now drop that for obvious reasons.
smeggy wrote:
We have "some police", but fewer on the roads than before, needlessly so because of the huge amount of paperwork they now have to do. The increased of cameras fooled people into thinking their loss was compensated; however, the continued loss of the nationwide fatality trend proves the folly of it.
Hence we can have more police on the roads without being "at the detriment of other crimes".
I think that even if the amount of paperwork that the police have to do was reduced, you would still not have as many police on the roads as before because of the public moaning that they should concentrate on ‘real’ crime.
smeggy wrote:
Well I never, RTTM is proven, accepted and extremely significant, and that’s excluding other effects of bias on selection …
I don’t recall ever saying that RTTM
wasn’t those things!
But we now get to a very important point:
You have very conveniently decided that that entire 10% “overall average reduction in FSCs attributable to these cameras” is not down to the cameras but instead is down to bias on selection.Warning, warning!!! Alert, alert!!!
I can now see what you and Bombus have been alluding to for a while – that there is in fact a reduction in fatal and serious collisions of (up to) 10%!!! Well you hardly rushed to say that now did you!
Yes, now that I know that, it certainly would be good to conduct research into what difference other measures make, but until then, I really don’t see how you can claim that speed cameras have no effect when you simply can’t say for sure.
And tell me, Smeggy, if I can’t trust you to be consistent and fair in your moderation, how can I possibly trust that you are telling me the whole truth when it comes to your sources?
smeggy wrote:
No, you are clearly trying to put words into my mouth.
Rubbish. I was merely asking you a question.
smeggy wrote:
I am explaining to you bias on selection. The A3 example is likely to be mostly RTTM (as explained). The limit drop may not have been significant at all; furthermore it isn’t the only example of bias on selection.
Except that I’ve told you that the A3 is a three-laned road. There aren’t any extra traffic calming features. There hasn’t been, to the best of my knowledge, any local road safety awareness courses. What else could there have been?
smeggy wrote:
No, I said it could play a part: "even if true". Are you trying to misrepresent me?
Smeggy, I
never try to misrepresent anyone.
smeggy wrote:
I said that in response to you saying that it "will" play a part. I asked you to justify the "will" in your statement. I presume anything of relevance still won’t be forthcoming.
No of course it won’t be; as I said before, I just assumed that that would be one of the things that you would say had played a part. I was saying it so that you didn’t have to. Your negativity really is completely unfounded here.
smeggy wrote:
Do you now understand bias on selection and that it is separate from RTTM and additional to the illusion of perceived effectiveness of cameras?
Yes, thank you.
smeggy wrote:
Are you not concerned that figures exist for the effectiveness of speed cameras but no such figures exist for other safety measures, even though they exist at cameras sites?
I am now, yes.
smeggy wrote:
Isn’t that exactly what you get with RTTM? If so then explain the difference.
No what I was talking about was getting less accidents than the short period beforehand on which it is decided to put up a speed camera – so less accidents overall.
Posted: Wed Dec 12, 2007 8:21 pm
In reply to r11co:
“Er, moderator, ad hominem alert”
Also:
“moderator, another ad hominem”
Smeggy, why have you taken no action over the above?
_________________________
Right, it’s taken a long time to put the above all together, so I shall have to leave any other comments for now. I do hope you all enjoy the sentence in bold. I certainly did.