johnson wrote:
Thanks for all your help i have found those links very useful. If anyone else has information please don't hesitate to post.
thanks
If you read and digest the
ex-parrot link, you will see that the stats used to "prove" the effectiveness of cameras are flawed by the "Regression to the mean" effect. Furthermore, it becomes apparent that in order to properly assess the effects of cameras a "control" experiment is needed, where two similar areas are selected but only one treated. Assuming a reasonably large sample were taken, and assuming there were no unexpected outside influences, then this would be a pretty convincing way of demonstrating the effectiveness or otherwise of cameras.
Well we happen to know of one location where this situation exists, except that we haven't - yet - got hold of the data. Here in Cumbria the local Camera Partnership started up two years ago this April. According to their management they found approximately 100 sites that met the statistical criteria for camera deployment, however roughly half of them were then de-selected due to operational problems, for instance it was too dangerous to park a van next to them etc. In the end 47 sites have actually been used for enforcement, and a drop in casualties of up to 40% has been claimed.
So here we have a clear situation where we have a statistically significant number of sites, half of which have had cameras deployed and half of which haven't. So all we need to do is see what has happened at the "de-selected" sites in order to discover what the
real effect of the cameras is.
I raised this issue on the Cumbria "Safety" Camera Partnership web forum on numerous occasions, and indeed others have also since taken up the call too, but all requests have been completely ignored by the SCP management.
I judge this to be due to one of two reasons: Either I (and other requestors) are judged by them to be "anti camera" so they don't feel we would use the information fairly, or else the information (as I suspect) demonstrates that the non-selected sites have seen exactly the same order of casualty reduction as the ones where cameras have been deployed, due to RTTM.
Now if you are genuinely researching this topic with an open mind and have no axe to grind, then can I suggest that you go to their web forum, explain your position, and make the same request to them? If you too get ignored then we can perhaps discount my first reason for their refusal, and look more closely at the second.
Their forum is here...
http://www.cumbriasafetycameras.org/forum/
Clearly if you
could get the data out of them you'd be able to write the "mother of all papers", as you'd have some red hot statistical data to base it upon that was of unprecedented quality and relevance.
Indeed, if necessary you might even feel it were worth using the new FOI act to try and obtain this data. It would seem to qualify for a valid request as (i) it is information that was collected by them and not another agency, (ii) it is information that will not come into the public domain via other channels, and (iii) it is very much in the public interest, perhaps vitally so...