RE: M4 cameras have not cut crashes
Thursday 14th July 2005
M4 cameras: too early to call?Road safety organisation Safe Speed has refuted yesterday's claims by the Swindon and Wiltshire camera partnership (SWCP) that the M4's speed cameras, which were switched on in April, have reduced crashes on the M4 motorway. According Safe Speed, its claims are statistically invalid.
M4 cameras have not cut crashes
Safety campaign refutes camera partnership's claims
M4 cameras: too early to call?
There are four main errors in the claims, said Safe Speed:
- Cherry picking. The SWCP has chosen a 'comparison group' intended to support its claims. This exaggerates the benefits.
- Bias by selection. (also known as regression to the mean). SWCP started with its camera vans on the M4 because the figures were at an unusually high level. With that as a starting point, it's perfectly natural for the figures to tend to reduce. This is a huge effect and endemic in camera partnership claims.
- Other effects. Although the partnership claims that 'nothing else has changed' on the M4, that's simply not true. There are extensive road works at J18, and those road works may well be having an effect on traffic.
- Too soon to tell. Accidents are essentially random in nature and this means that long periods of observation are required to make valid comparisons. The usual recommendation of professional traffic engineers is five years before and five years after. The cameras only went live in April.
Safe Speed said it was "quite certain" that the numbers published do not justify the claims made.
Paul Smith, founder of Safe Speed's campaign said: "I've completely lost count of the times that wild and unjustified claims have been made by camera partnerships. It's become par for the course. It makes me incredibly angry because we depend on accurate road safety information in order to deploy resources to save lives. Claims like these cause death because they cause resources to be misallocated."
Smith said: "Camera partnerships are riding a runaway gravy train that must be stopped. Speed cameras don't save lives - they just distract everyone from real road safety. We won't get back on track until we scrap the infernal devices."
Discussion
crankedup said:
Is'nt it time these stats were audit by an impartial company/group so we have the truth from the outset?
That would require the government to consider that the SCPs need regulating. As Darling is responsible for half of these lies, I mean statistics, and as he's all in favour of cheap, outsourced enforcement, that's as likely as turkey's voting for christmas!!!
Unless those with a voice, like Paul Smith, can persuade the masses to take more of an interest in getting these things restricted and properly regulated, then I think we're screwed.
Oh...as an aside, one of the non-petrolheads at work saw Paul Smith on a TV debate last week. He said "I'm sure the guy was talking sense, but his appearance will have just switched people off straightaway." Unfortunate comment, but out-of-the-mouths-of-babes, so to speak...
...what I'm trying to say is until we get an articulate, photogenic advocate (probably male, 30-50, south-eastern or neutral accent, ideally already "known" in the public eye, judging by the people who ARE taken seriously by this population), then we're fighting a losing battle...the other side has all the credibility as they are perceived as the establishment!!!
princeperch said:Where the hell have you been?
Jesus when did these cameras go up?!!!
My cyclops didnt warn me of them the other week, and I must have been doing 80ish most of the way to Reading.
There arnt any signs saying they are in operation either...
Whats the deal?
Talivans on the bridges in Wiltshire - remember the M4 protest???
puggit said:
princeperch said:
Jesus when did these cameras go up?!!!
My cyclops didnt warn me of them the other week, and I must have been doing 80ish most of the way to Reading.
There arnt any signs saying they are in operation either...
Whats the deal?
Where the hell have you been?
Talivans on the bridges in Wiltshire - remember the M4 protest???
Remember it? I took part!
I hope its just a clerical error in the selection of the picture being used - that gantry is the first one I pass under after leaving the m25 and joining the m4, and it has camera line after it - but I didnt know there were cameras on the gantries on the m4 until you get past the Reading/Newbury ect junctions further up?!
See my query here www.pistonheads.co.uk/gassing/topic.asp?t=193115&f=10&h=0
I presume you use this stretch Chris to get back to the 'Ding from London, any ideas?
>> Edited by princeperch on Thursday 14th July 13:50
g laugh I saw these guys for the first time last Thursday evening. They were on the bridge just before the M32 turn off. There must have been about 10 police on the bridge plus 3 or 4 vans, cars etc. Given what had happened that day and the resources involved I can't believe that REAL crime is being dealt with in any way, shape or form. All they needed was a picnic!! Needless to say I probably got caught and was glad there wasn't anyone behind me when I slammed the anchors on! That's what causes the accidents... nuff said.
I'm glad this was picked up...
This can demonstrate that speed cameras could actually be having a negative impact on road safety, whilst statistically appearing to be giving a benefit even after factoring in effects of RTTM.
Yoohoo Martincrowe
>> Edited by smeggy on Thursday 14th July 14:15
SafeSpeed said:…...something I call 'selection on bias'.
3
Other effects. Although the partnership claims that 'nothing else has changed' on the M4, that's simply not true. There are extensive road works at J18, and those road works may well be having an effect on traffic.
This can demonstrate that speed cameras could actually be having a negative impact on road safety, whilst statistically appearing to be giving a benefit even after factoring in effects of RTTM.
Yoohoo Martincrowe
>> Edited by smeggy on Thursday 14th July 14:15
havoc said:
Oh...as an aside, one of the non-petrolheads at work saw Paul Smith on a TV debate last week. He said "I'm sure the guy was talking sense, but his appearance will have just switched people off straightaway." Unfortunate comment, but out-of-the-mouths-of-babes, so to speak...
It's money. I need contact lenses for TV, and if propely funded I'd hire an image consultant. I can't afford either.
It's hard to believe that I've invested around 10,000 hours (worth, what? £100,000?) and £10,000 in hard cash but very very few others can be bothered to stump up more than £45.
Give support via:
www.safespeed.org.uk/join.html
princeperch said:Oh yes - I sit here in a traffic jam every god damn day
I presume you use this stretch Chris to get back to the 'Ding from London, any ideas?
This is the first gantry (well spotted!) - there's no camera here...
The second gantry DOES have a Gatso-style camera mounted above lane 2 plus the lines on the road (M25 stylee). It is active most of the time... But if it is a live revenue earner, it's threshold is set above 90-odd
I'm assuming it's a clerical error by a non-driver who thinks 'safety' cameras are a good thing
safespeed said:
It's hard to believe that I've invested around 10,000 hours (worth, what? £100,000?) and £10,000 in hard cash but very very few others can be bothered to stump up more than £45.
Give support via:
www.safespeed.org.uk/join.html
I agree that SafeSpeed needs and deserves support, and I'm sorry if the level of support is disappointing, especially from groups such as PistonHeads.. However, it appears that some donations do not qualify individuals for any kind of membership, and it might be worth considering a change to that situation.
Best wishes all,
Dave.
chobbs said:
I saw these guys for the first time last Thursday evening. They were on the bridge just before the M32 turn off. There must have been about 10 police on the bridge plus 3 or 4 vans, cars etc.
They were ANPR cameras , I saw them too , monitoring traffic leaving London after the attacks.
Having said that, following their publicity on the BBC yesterday evening, THEY'RE BACK... this morning there was a Wiltshire camera van operating from a bridge near jnct 17 M4 Chippenham.
First time I've seen them since the protest.
Does anyone have the stats for the number of crashes between when the camera vans started and the protest, after which they dissapeared.
I remember a cluster of crashes coinciding with the when they started the mobile speed traps, the crash rate must have gone up by atleast 100% in that month, and now they claim a 60% reduction even though they havn't been there for the last two months!
havoc said:
...what I'm trying to say is until we get an articulate, photogenic advocate (probably male, 30-50, south-eastern or neutral accent, ideally already "known" in the public eye, judging by the people who ARE taken seriously by this population), then we're fighting a losing battle...the other side has all the credibility as they are perceived as the establishment!!!
Very true.
It must be said Paul Smith is excellent at his work and I'm sure it's very much appreciated by us all and essential in 'the battle', but he cant do it all and it wouldn't be fair, he isn't a presenter.
After the AA speed camera atlas stories a few weeks ago, Quentin Wilson was interveiwed by Sky and my god, he was excellent!
He is a presenter afterall and put across so well the myths surrounding speed cameras, he hardly let the interveiwer get a word in! He was compelling to watch.
He would make an excellent figurehead for the ABD, their credibility and influence would expand enormously ... anyone know his mobile? :-)
deeps said:
Very true.
It must be said Paul Smith is excellent at his work and I'm sure it's very much appreciated by us all and essential in 'the battle', but he cant do it all and it wouldn't be fair, he isn't a presenter.
After the AA speed camera atlas stories a few weeks ago, Quentin Wilson was interveiwed by Sky and my god, he was excellent!
I'm not at all sure this is right. If I believed it was right, then I'd have put a great deal of effort into trying to find a figurehead. The problem is that the figurehead types aren't ready with all the answers, while I am ready with the answers.
But if anyone can find a figurehead who'll put in the hours to learn the information then that really would be best. Hell, I don't even want to do the presenting. But it's falling to me and I'll take it on and do my very best.
I'm doing Newsnight Scotland (BBC2 Scotland) at 11pm this evening.
No, no, no, no, no! You most certainly do not want Quentin Wilson or some bloke in his mid 30's to be the public face of safe speed. When the general public see either of those people, their brain will (either consciously or subconsciously) think "this is a car nut/pertrol head/environmental rapist - I cant trust him, he's biased and just wants an excuse to carry on speeding recklessly" etc.
Paul, you dont need an image consultant, what you need is a woman, and not just some young totty, but a well spoken mature woman that looks like an educated, married, mother of three. Women portray a much more motherly, caring, and trustworthy image. Trust is teh key word. Look at BRAKE, and that anti 4x4 group - they're both led by women and people tend to listen to what they have to say.
Paul, you dont need an image consultant, what you need is a woman, and not just some young totty, but a well spoken mature woman that looks like an educated, married, mother of three. Women portray a much more motherly, caring, and trustworthy image. Trust is teh key word. Look at BRAKE, and that anti 4x4 group - they're both led by women and people tend to listen to what they have to say.
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