I go with the Safer Roads Day stats - the police generally say the same.
It's a simple matter of physics. Kinetic energy increases as the square of speed, so if you double your speed you quadruple the scale of the impact. Kinetic energy = half x mass x velocity squared. (Gosh, I'm beginning to sound like L.J.K.Setright!)
So in an emergency, higher speed means your stopping/slowing distance is longer, and you travel further during your reaction time. This could mean the difference between hitting something or pulling up short. If you were going to hit it anyway, then if you were going faster you'd have hit it harder. All very basic - everyone learns that for their driving tests
People who would normally be speeding tend to slow down for speed cameras. If these cameras are placed at known accident black spots, then they should reduce the accident rate there for the above reason.
Cheers, SS
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Yes, it may be true, this is statistics, if you reduce the size of the sample (throughput), you will reduce the instances of the event you are looking for.
Rather like of they just closed the road, there would be no deaths or serious injuries.
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It did sound rather like they were talking about thirds - 35%, 67% etc.
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Just handed this leaflet in Headingley, Leeds. It claims that: * Driving at excess or inappropriate speed is the single biggest cause of fatal and serious crashes. * Where speed cameras have been installed casualties have fallen by 35%. Number of vehicles speeding has fallen by 67%. This goes against everything told to us by a lot of car journalists. Which version is true? (see www.saferroadsday.com )
Not so long ago an article written by an anti-speeding campaigner/employee appeared in the Sunday Times Driving section. She said that 1/3 of accidents are due to speeding.
A year or two ago I checked official government data, and there was no way that it supported any such claim, or the claim that excess or inappropriate speed was the biggest cause of accidents. Common causes of accidents included pulling out of a junction into oncoming traffic, and tail-gating. Hopefully someone can provide a link to the gov. data.
One police authority speeding group (Notts?) publishes stats for their speed cameras. Most show significant reduction in the number of serious accidents, though a significant minority showed significant increases! The naive conclusion is that speed cameras often reduce accidents, but can also increase them. However, if cars are getting safer, and camera numbers are increasing massively, why are the national accident stats roughly level, after a long period of steady decline?
A local case is interesting. One straight wide road with wide pavements that passes a school has a 20mph limit and speed humps. Most people thus take the backroads. These are narrow residential roads, with parked cars either side, and a 30mph limit. My guess is that accidents on the backroads have gone up.
Leif
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However, if cars are getting safer, and camera numbers are increasing massively, why are the national accident stats roughly level, after a long period of steady decline?
Because the rate at which accident rates per mile are falling is slightly lower than the rate at which vehicle numbers and mileage are increasing. Each mile travelled is safer, just there are more miles travelled.
A local case is interesting. One straight wide road with wide pavements that passes a school has a 20mph limit and speed humps. Most people thus take the backroads. These are narrow residential roads, with parked cars either side, and a 30mph limit. My guess is that accidents on the backroads have gone up.
Which is why policies of speed reductions only outside schools are misguided.
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>> However, if cars are getting safer, and camera numbers are increasing >> massively, why are the national accident stats roughly level, after a >> long period of steady decline? Because the rate at which accident rates per mile are falling is slightly lower than the rate at which vehicle numbers and mileage are increasing. Each mile travelled is safer, just there are more miles travelled.
So speed cameras have reduced the rate at which accidents are falling. You might be right but I wonder why?
>> A local case is interesting. One straight wide road with wide >> pavements that passes a school has a 20mph limit and speed >> humps. Most people thus take the backroads. These are narrow residential >> roads, with parked cars either side, and a 30mph limit. My >> guess is that accidents on the backroads have gone up. Which is why policies of speed reductions only outside schools are misguided.
But that is what we have, a narrow focus on one 'solution', without thinking.
Our local council have a poor approach to road safety. They recently introduced 20 mph limits on a local road, but only at the junctions. The road was very wide, straight, with good visibilily and wide pavements. I was too worried about the possibility of causing an accident and of abuse from other drivers to slow from 30 to 20 only at the junction. I never saw any other cars obey the limits either. Oddly enough they were removed after a year. And then there's the local speed humps that make my car (unmodified production Ford Ka) make loud banking noises when taken at walking speed or faster. Passengers always comment on the noise.
Leif
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>> Because the rate at which accident rates per mile are falling >> is slightly lower than the rate at which vehicle numbers and >> mileage are increasing. Each mile travelled is safer, just there are >> more miles travelled. So speed cameras have reduced the rate at which accidents are falling. You might be right but I wonder why?
Umm, I don't know the rates of accident per mile. They may be falling more slowly than before, or faster.
If they are falling more slowly, blaming spd cameras is only a guess: all we actually know for certain is that they have been repeatedly demonstrated to reduce accidents where installed. There are plenty of other factors at play, such as the deplorable reductions in numbers of traffic cops.
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>>...all we actually know for certain is that they have been repeatedly demonstrated toreduce accidents where installed...
No we don't. Ever heard of Regression to the mean?
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No we don't. Ever heard of Regression to the mean?
You've been reading too much Paul Smith. When the Today programme put a statistician on the case, he didn't buy PS's claim that it can all be explained away. Today's summary was that Smith "couldn't see the wood for the trees"
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Why then with 5000 "safety" cameras saving lives did fatalities rise last year?
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Why then with 5000 "safety" cameras saving lives did fatalities rise last year?
As above. Total fatalities rose, but fatalities per mile continued to fall.
Why wasn't the fall in fatalities per mile bigger? I'm sure that the cost-cutting removal of trafic cops was one important factor -- and it's not related to cameras, cos fixed cameras are self-financing and mobile cameras don't take more police time than old-fashioned radar-gun speedtraps.
Saying that cameras must be bad because fatalities aren't falling fast enough is about as silly as saying that in-car airbags must be bad because fatailities are not falling fast enough. There are many other factors at play.
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Total fatalities rose, but fatalities per mile continued to fall.
In contrast to just about every year since the late sixties, the fact remains that fatalities per mile AND total fatalities fell year on year until recently.
Why wasn't the fall in fatalities per mile bigger? I'm sure that the cost-cutting removal of trafic cops was one important factor -- and it's not related to cameras, cos fixed cameras are self-financing and mobile cameras don't take more police time than old-fashioned radar-gun speedtraps.
Cameras being self-financing is one of the problems, any other safety device costing tens of thousands of pounds but making no money, would soon be dropped if they were as effective as cameras!
Saying that cameras must be bad because fatalities aren't falling fast enough is about as silly as saying that in-car airbags must be bad because fatailities are not falling fast enough. There are many other factors at play.
Maybe so, but cameras were supposedly to reduce accidents, they are failing to do that. What they are doing is making money.
So what we have are quangos charged with reducing casualties, but failing to do so, but making money to finance more cameras which are failing to reduce casualties, but making even more money etc...
If cameras did what they were supposed to do there wouldn't be a problem.
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>> No we don't. Ever heard of Regression to the mean? You've been reading too much Paul Smith. When the Today programme put a statistician on the case, he didn't buy PS's claim that it can all be explained away. Today's summary was that Smith "couldn't see the wood for the trees"
Paul Smith is an overrated designer IMO. But then again, I just buy whatever M&S have in store. Oh you mean the other Paul Smith. Yes, some of the Safe Speed (sic) arguments are specious IMO. Some of it is good though.
BTW the Sunday Times article I referred to in an earlier post said that speed cameras had reduced accidents dramatically and a large % figure was quoted. Close reading of the text showed that the claimed reduction was relative to a baseline from many years before speed cameras became prevalent, and that if you used the start of the speed camera era as the baseline, no statistically significant change could be seen. The article was basically complete lies. It makes me angry to see government employees publishing downright lies. (After all, that's the function of government ministers.)
Leif
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Living in North Wales I'm more than familiar with speed cameras & camera vans appearing all over the place. Have to agree that the figures relating to the reduction (or not actually!!) of deaths/accidents simply don't correspond to the massive increase in camera use & the subsequent massive increase in people receiving speeding fines & therefore the police forces/governments very nice rise in revenues.
If cameras are suppose to act as "safety" devices why are most of the mobile "arrive alive" vans used in North wales situated within 10yds of blind corners/ blind junctions - surely they should be placed in the most easily noticed positions to have the most effect. They are simply been used to generate money, just can't believe that some people think this isn't the case - come to North Wales & see for yourself - it's so blatantly obvious to anyone.
Speed is often blamed for fatalaties/accidents but it's surely not that simple. IMHO the police should spend more of their time monitoring the increasing number of dangerous manoeuvres we see every day on the roads, sure speed can be dangerous but the complete disregard for other people on the road that's shown by many drivers now & the polices' failure to address it must surely be one of the main reasons why the statistics relating to deaths/accidents on our roads have failed to fall significantly.
A re-assessment of the effectiveness & increased reliance upon speed cameras is definitely overdue, as is some honesty from the powers that be regarding their real impact in making the roads a safer place !!
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If they're on dangerous blind corners or blind junctions where they have been accidents where excessive speed was actually involved in a lot of cases then it isn't such a stupid place for them to be. I'd be surprised if that was the actual reason they were there though....
The thing I want to know is how much money do the companies that make all this equipment give to the Labour party and are there government members /family/friends of same that are company directors?
If fatalities per mile are increasing, more than in the eighties when traffic also increased radically then it points at government policy being wrong.
teabelly
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"If fatalities per mile are increasing, more than in the eighties when traffic also increased radically then it points at government policy being wrong."
I know this Govt is blameworthy for lots of things, but surely the drivers must shoulder some of the blame? I would say there is way more aggression, powerful cars and general disregard for other road users than in the 80s.
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Powerful cars have little to do with it. The late eighties was the era of the supercar and most of those were just as fast, if not faster than today's cars. Today's cars are also safer physically and are stock full of traction control etc. The everyday cars are also much safer with their abs and airbags. The same cars are available in the rest of Europe and yet their road deaths are still falling at a decent rate. The increased aggression is due to the increased congestion which is a direct result of the government's (i'm talking tory too) policy of trying to force people out of their cars by limiting road space. The huge house price inflation and uncertain (flexible) job market has meant people have to commute longer distances to make a living. Working longer hours and doing longer commutes is going to make drivers more prone to making mistakes which in congested routes are less likely to go unnoticed.
I would be interested to know the accident rate on the M6 toll road vs the ordinary M6 as I know the toll road speeds are much higher on the latter but the congestion is a lot less.
teabelly
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Reference to the earlier post mentioning what would happen to Jenson Button if he was ever caught speeding. Are you absolutely certain he would lose his licence? He was caught speeding in France in May 2000 (at 144 mph) and he got away with a rather derisory fine (£500). No ban, no points on his licence.
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If they're on dangerous blind corners or blind junctions where they have been accidents where excessive speed was actually involved in a lot of cases then it isn't such a stupid place for them to be. I'd be surprised if that was the actual reason they were there though....
Plenty of folks do the right thing for the wrong reasons!
The thing I want to know is how much money do the companies that make all this equipment give to the Labour party and are there government members /family/friends of same that are company directors?
You can check on the Electoral Commission website: tinyurl.com/b9wdf
If fatalities per mile are increasing, more than in the eighties when traffic also increased radically then it points at government policy being wrong.
Except that fatalities per mile are clearly falling
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"Except that fatalities per mile are clearly falling"
That's thanks to congestion. Instead of a car being proceeded by a man with a red flag, each car is proceeded by another car going at walking pace. And no that is not a flippant comment. If traffic speeds are reduced massively, then accident rates must plummet (or at least the rate of serious accidents).
What worries me somewhat is that in principle no-one (not even the law abiding) can avoid being caught by the law. We know that if we don't steal an item, then we are not thieves. But someone who travels regularly cannot be sure that their speedo is functioning correctly. If it isn't then they might receive 4 NIPs before they realise the problem. I wonder how often a speedo malfunctions in this manner? And NoWheels before you cut in and say "That is so unlikely as to be ignorable" or "It is a driver's duty to ensure that their vehicle functions correctly" my last car had a speedo failure. Fortunately it overestimated, and told me that I was doing 70mph in a 30 zone, even when following an old dear in her Micra. I twice booked the car in to the local garage and twice they returned it with 'no fault', and yet it carried on intermittently giving false readings.
Maybe some techie can rule out this issue as a problem, but I remain concerned. Is it an issue?
The recent M4 camera business, where they suggest that there is no leeway i.e. 71 mph is illegal is extremely worrying.
Leif
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Its not at all possible that the accident and injury/fatality rate is falling as a result of cars with safety aids like air bags, ABS and traction control now being available, by virtue of second hand cost, to the vast majority of motorists is it?
Call me a cynic but I douvt that speed cameras are having much of an effect on the epople who use the roads where they are situated on a reegular basis. The vast majority brake before the camera and accelerate after it. Benefit? Virtually none!
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"Call me a cynic but I douvt that speed cameras are having much of an effect on the epople who use the roads where they are situated on a reegular basis. The vast majority brake before the camera and accelerate after it."
I doubt anyone would disagree with that observation.
Leif
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That's very useful, thanks. I shall be having a good old browse :-)
teabelly
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