Discussion
SPEED cameras do NOT cut fatal accidents, new Government research reveals.
Scientists examined 149 accident blackspots in 30mph zones throughout the country.
And they found cameras had little or no effect on deaths and serious injuries.
The five-year Government-funded study was carried out by Liverpool University researchers.
Dr Linda Mountain, who led the team, said the case for Gatso cameras in built-up areas has been “exaggerated”.
She said the only traffic calming method found to have a significant impact on fatal and serious accidents on urban roads was speed humps.
She added: “It was a surprise that we couldn’t detect a significant change in fatal and serious accidents at camera sites.”
More than two million motorists were caught in speed traps last year.
The findings cast doubts on Government claims that cameras have cut deaths by 100. The Association of British Drivers last night said that the study proved speed traps are a “stealth tax”.
Spokesman Tony Vickers said: “Cameras are simply not working — unless the aim is to make a profit.”
Scientists examined 149 accident blackspots in 30mph zones throughout the country.
And they found cameras had little or no effect on deaths and serious injuries.
The five-year Government-funded study was carried out by Liverpool University researchers.
Dr Linda Mountain, who led the team, said the case for Gatso cameras in built-up areas has been “exaggerated”.
She said the only traffic calming method found to have a significant impact on fatal and serious accidents on urban roads was speed humps.
She added: “It was a surprise that we couldn’t detect a significant change in fatal and serious accidents at camera sites.”
More than two million motorists were caught in speed traps last year.
The findings cast doubts on Government claims that cameras have cut deaths by 100. The Association of British Drivers last night said that the study proved speed traps are a “stealth tax”.
Spokesman Tony Vickers said: “Cameras are simply not working — unless the aim is to make a profit.”
cuneus said:
Dr Linda Mountain, who led the team, added: “It was a surprise that we couldn’t detect a significant change in fatal and serious accidents at camera sites.”
Suprise?!!! friggin surprise?! we've only been telling them for the last 3 years, absolute shower of expletives the lot of em
cuneus said:
Dr Linda Mountain, who led the team, added: “It was a surprise that we couldn’t detect a significant change in fatal and serious accidents at camera sites.”
Obviously they were "expecting" to find a drop.
Perhaps substitute "expecting" with "funded to" then we have the explanation behind all pro-scam stats
Jewhoo said:
Dr Linda Mountain, who led the team, added: “It was a surprise that we couldn’t detect a significant change in fatal and serious accidents at camera sites.”
Obviously they were "expecting" to find a drop.
Perhaps substitute "expecting" with "funded to" then we have the explanation behind all pro-scam stats
When carrying out this kind of study you start with your hypothesis. the hypothesis states what you're expecting to find/prove. It is not indicative of bias though.
For example a hypothesis may be "We will show that there is a strong correlation between the percieved attractiveness of long-term couples".
If the results show something other than what's expected (usually based on previous studies, "common sense" or the reason behind the thing you're investiigating) then you may do further research to gain insight.
Nothing sinister - just standard experimental practice.
iaint said:
Nothing sinister - just standard experimental practice.
No its not, you set off with a null hypothesis that says the treatment you have administered to a system will have no effect. You can only make a hypothesis on available data, if you have no available data then your hypothesis has to say there will be no effect. The aim (not hypothesis) of this study was to quantify any effect, however the starting hypothesis must have been that no effect would be observed. The word "surprise" should have been substituted for disappointment
Most of the studies done on speed cameras have little or no scientific methodology behind them and this one is no different. Its really annoying to see data published that should never see light of day past the peer review system.
MilnerR said:
Most of the studies done on speed cameras have little or no scientific methodology behind them and this one is no different. Its really annoying to see data published that should never see light of day past the peer review system.
Similarly most of the studies on global warming and other high profile pseudo-science. With a non-scientific audience and journals fighting for profile, it's no wonder that these "little slips" are made "from time to time".
What I don't understand is that the study says one thing and the government spokesperson says the opposite. Isn't it odd?
MilnerR said:
Nothing sinister - just standard experimental practice.
No its not, you set off with a null hypothesis that says the treatment you have administered to a system will have no effect. You can only make a hypothesis on available data, if you have no available data then your hypothesis has to say there will be no effect. The aim (not hypothesis) of this study was to quantify any effect, however the starting hypothesis must have been that no effect would be observed. The word "surprise" should have been substituted for disappointment
Most of the studies done on speed cameras have little or no scientific methodology behind them and this one is no different. Its really annoying to see data published that should never see light of day past the peer review system.
Correct! Like so many other things we need independantly funded double blind testing to eliminate bias.
See www.pistonheads.com/gassing/topic.asp?f=10&h=&t=179451
Now maybe that explains why DfT are sponsoring some research as in the other thread. One of two possibilities.
1)Somebody has nabbed us, so we must set up our own study, just make sure that the brief is correct so we get the right result.
or
2) Oh dear wrong result, we'll ignore that and carry on until we get the answer we want.
Bit like the IPCC computer models on climate change.
Peter Ward said:
Most of the studies done on speed cameras have little or no scientific methodology behind them and this one is no different. Its really annoying to see data published that should never see light of day past the peer review system.
Similarly most of the studies on global warming and other high profile pseudo-science. With a non-scientific audience and journals fighting for profile, it's no wonder that these "little slips" are made "from time to time".
What I don't understand is that the study says one thing and the government spokesperson says the opposite. Isn't it odd?
What does seem strange is the fact that these outspoken carers of peoples liberty, the environment, the ozone layer (that's gone quiet hasn't it?) global warming, social engineering and crime, transport and world energy problems all seem to get it 180 degrees out of kilter with what is actually required to solve the problem. I don't suppose road safety should be any different, if only they got off their bloody soapboxes and put a little effort in to it
Totally agree cameras only generate revenue, they do ziltch for preventing accidnts, but do cause some as we all know.
Although I have supported the 70 mph limit on other threads on this site, I will be the first to admit to the fact that if motorway speed limits were increased to, say 90mph (wishfull thinking) I would happily glide along at 90 mph (conditions allowing of course).
Safe driving you guys
Although I have supported the 70 mph limit on other threads on this site, I will be the first to admit to the fact that if motorway speed limits were increased to, say 90mph (wishfull thinking) I would happily glide along at 90 mph (conditions allowing of course).
Safe driving you guys
Variable limits depenent on traffic density and weather conditions would be safer. I was on the M23 yesterday in my Westfield (there's no better way of feeling exposed except on a motorcycle) and, quite frankly, more than about 65-70 would have been pretty hairy with so many vehicles and the frequency of junctions near Gatwick. On the other hand, up in Cumbria, over Shap on a quiet day, 90 would be fine. More, maybe. The technology exists....
james_j said:
Comments from camera representatives invited....at all?....hellooooooo! 
>> Edited by james_j on Monday 23 May 16:32
Here you go James:
It would seem that the only part of the information from the report that the comments here refer to are the newspaper headlines. Some of the conclusions of the report went like this:
1. Cameras are most effective on roads with higher speeds
2. Typically a 4% fall in accidents per 1 mph reduction in speed
3. 8.4 mph fall in mean speed
4. 38% fall in personal injury accidents and 30% fall in fatal and serious accidents attributable to impact on speed
5. Cameras reduce accidents – less than observed change but worthwhile benefits
6. The methodology used allows for regression, trend, route changes and speed changes
Now how this reporter managed to make out that the cameras had no effect from those conclusions beats me but maybe he/she has some advanced analytical experience that can see through these conclusions and turn them on their head. I somehow doubt even the members here would believe that!
So there you have the response you requested, now can you get the headline and the comments to match the conclusions because I can’t. Perhaps you should look at the report rather than the c*#p the tabloid rags feed you next time and you will spend less time with your foot in your mouth.
Regards
The man behind a few cameras.
destroyer said:
james_j said:
Comments from camera representatives invited....at all?....hellooooooo!
>> Edited by james_j on Monday 23 May 16:32
Here you go James:
It would seem that the only part of the information from the report that the comments here refer to are the newspaper headlines. Some of the conclusions of the report went like this:
1. Cameras are most effective on roads with higher speeds
2. Typically a 4% fall in accidents per 1 mph reduction in speed
3. 8.4 mph fall in mean speed
4. 38% fall in personal injury accidents and 30% fall in fatal and serious accidents attributable to impact on speed
5. Cameras reduce accidents – less than observed change but worthwhile benefits
6. The methodology used allows for regression, trend, route changes and speed changes
Now how this reporter managed to make out that the cameras had no effect from those conclusions beats me but maybe he/she has some advanced analytical experience that can see through these conclusions and turn them on their head. I somehow doubt even the members here would believe that!
So there you have the response you requested, now can you get the headline and the comments to match the conclusions because I can’t. Perhaps you should look at the report rather than the c*#p the tabloid rags feed you next time and you will spend less time with your foot in your mouth.
Regards
The man behind a few cameras.
It would seem as if you have just reposted your previous drivel from the RE: Speed cameras don't save lives thread...
destroyer said:
Strange the reports made from this study when the results went something like this:
1. Cameras are most effective on roads with higher mean speeds
2. Typically a 4% fall in accidents per 1 mph fall in speed
3. 38% fall in slight injury accidents
4. 30% fall in fatal and serious injury accidents
5. Cameras reduce accidents
6. 19% fall in slight and 6% fall in fatal and serious accidents due to impact speed
It also says that the method of arriving at these conclusions allowed for regression to the mean effects and used a technique to reduce these effects in arriving at the figures.
Look at conclusion number 2. It is only 1% lower than what the TRL predicted all those years ago.
I can't find any reference in the report that says cameras don't work as intended. Has Ms. Mountain produced another report that contradicts this one that is still available on the Liverpool Uni website?
The conclusions of this report certainly say nothing like what has been reported.
Therefore I will repost my response to which you didn't bother replying.
destroyer said:
Strange the reports made from this study when the results went something like this:
1. Cameras are most effective on roads with higher mean speeds
2. Typically a 4% fall in accidents per 1 mph fall in speed
3. 38% fall in slight injury accidents
4. 30% fall in fatal and serious injury accidents
5. Cameras reduce accidents
6. 19% fall in slight and 6% fall in fatal and serious accidents due to impact speed
Dr Linda Mountain said:
We could not detect a significant change in fatal and serious crashes at camera sites
Speed humps and cushions had a significant impact on fatal and serious accidents but cameras didn't. It was a surprise. I expected to find some reduction
the case for cameras on those roads had been "exaggerated".
How can these statements be reconciled?
Presumably because the research team found that any reduction that appeared to be caused by cameras was statistically insignificant. It's very possible that the regressions didn't include enough variables to capture the full effects, hence some errors or non-regressed variables could be aportioned to the cameras, making it appear that the cameras did have an effect when in fact they didn't. Therefore a result of a fall in casualties at camera sites can be found (and seized upon by yourself) yet it can also be insignificant.
Unless I can get a proper look at the report, I won't know if/how many dummy variables etc etc were used and precisely why the effect of cameras was insignificant.
What we do know is that the results of the regressions run are;
Speed humps were found to have a large effect - research team happy that this is a significant result.
Speed Cameras were found to have a much smaller effect - the research team were of the opinion that (for a currently undisclosed reason) the result was insignificant.
Therefore, your original post is insignificant!
Also, it'sinteresting to note how you have changed some of those stats to make more impressive reading, particularly
destroyer in second post said:
4. 38% fall in personal injury accidents and 30% fall in fatal and serious accidents attributable to impact on speed
destroyer in first post said:
6. 19% fall in slight and 6% fall in fatal and serious accidents due to impact speed
Care to explain why you feel the need to double one statistic and increase the other five-fold?
>> Edited by Jewhoo on Wednesday 1st June 10:05
Jewhoo said:
Speed Cameras were found to have a much smaller effect - the research team were of the opinion that (for a currently undisclosed reason) the result was insignificant.
Therefore, your original post is insignificant!
Read it all for yourself on the Liverpool Uni website.
I'm not surprised that you are willing to accept view you favour with UNDISCLOSED REASONS to support them. It's pretty typical of single sighted nuggets!
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