Welcome Back slyliner. Don’t worry about the delayed reply, we’re not in the habit of forcing people to act faster than they should

You are of course free to express your belief, but others are also free to scrutinise those beliefs. Sorry for my detailed post but there’s a lot to address. Here goes..
Skyliner wrote:
"The £1m-a-year motorway speed camera that is causing accident"
I note with interest the "Subject Heading" focuses on the amount of alleged revenue generated by this camera, rather than the amount of accidents the camera in question allegedly creates.
Even though that's a journalistic heading, I find it very telling.
That tells me is that the speed limit on the section of the road in question is set unreasonably low. To clarify: drivers were exceeding the limit and subsequently having a rate of accidents. The camera has been installed in an attempt to force compliance but has actually resulted with errant behaviour, likely due to factors such as panic breaking, frustration, fatigue etc. This case shows enforcement of what seems like one of the most unreasonably low limits (many 50 limits on motorways simply aren’t justifiable, in terms of speed and/or length) has lead to an unusually high accident rate, despite driving becoming safer overall.
This camera is a total failure. It is difficult to dismiss this case as a one-off because it is indeed the most active camera in Britain, hence its significance has many times the weighting compared to an average camera.
Skyliner wrote:
"Speed is the biggest single contributory factor in road crashes, inflicting hundreds of thousands of casualties every year.
Actually, that has been disproved and quietly recanted. Later and more comprehensive reports state
“Failed to look properly was the most frequently reported contributory factor” (dft_transstats_612594). Don’t forget, cameras can only act upon ‘exceeding the speed limit’ (and not very well at that) which is actually a minority chuck of the ‘speeding’ pie.
Skyliner wrote:
The relationship between speed and road crashes is straightforward: as speeds go up, the likelihood of crashes goes up, for any given set of road conditions. The reason is simple: increased vehicle speeds are not accompanied by increased thinking and reacting speeds. Because of this the distance needed for responding and braking increases with speed.
It’s nowhere near as simple as that. Driver fatigue accounts for more collisions than exceeding the speed limit (17% for all roads (dft_rdsafety_032139), greater for motorways, greater still during the small hours when the traffic flow is going to be the fastest). On many roads (usually those with unreasonably low limits and enforcement), going slower will inherently mean even less stimulating conditions; it will also mean being on the road for longer. These two coupled together gives a double whammy against the overly simplistic arguments of the speed/accident relationship.
Skyliner wrote:
Inappropriate speed choice - driving too fast for the conditions - is the major factor in up to a half of road crashes and contributes to many more.
Speed cameras can’t do anything about that.
Skyliner wrote:
Speed reductions cut casualties. The likelihood of crashes decreases as speeds are reduced. Although the relationship varies according to road conditions and average speeds, there is an association between speed reduction and crash reduction - every 1 mph reduction in speed reduction in crashes is accompanied by an average 5% decrease in crashes and a 7% decrease in fatalities.
A 10% drop in speeds resulted in a 40% drop in fatalities and serious injuries after speed cameras were introduced in West London.
Where 20 mph zones have been introduced and enforced, all casualties have fallen by around 60%.
One word:
causality!
Is the cause and effect in this case as clear as it is implied, or are there other factors at work? For example, we know policy stipulated that cameras are installed in areas where there is a temporarily high level of accident rate, so you can expect a reduction afterwards regardless of whether cameras are installed (I gave you a link to the Regression To The Mean page, you have to read this in order to properly understand this critical argument). We also know cameras do force slower driver speeds – so what exactly was cause and effect in this case?
Then there are the other safety measures typically installed within defined camera sites, aiding or swamping any benefit from the cameras, or even reversing the negative benefit from them.
Then there is the classic ‘Hawthorne effect’ where a visible change will encourage a temporary improvement of behaviour.
Skyliner wrote:
Driver error is found to be a contributory cause in over 90% of accidents, and driving too fast is a driver error in judging what is safe." DETR, Road Safety Division, Speed Policy Review Discussion Paper, August 1999."
That’s true, but driving too fast (let alone exceeding the sped limit) accounts for a surprisingly small portion of the 90% pie.
Skyliner wrote:
You say "That’s a bit of a glib example" in relation to part of my post.
Hmmmm, possibly, but it got the point across.
Speed cameras don’t saunter out from fields in the paths of traffic. However, just like the cow example, those within the limit can also suffer additional risk.
Skyliner wrote:
"quote" ‘Speed cameras are great!’ – in fact, they’re anything but. "end quote"
I myself never said I was for or against Speed Cameras.
My point is speeding kills.
Inappropriate speed: certainly.
The key here is what speed is appropriate. What should be limits be set to?
Furthermore, how should they be enforced? Cameras allow the worst driver groups impunity (those with stolen or improperly registered or unidentifiable vehicles) to speed inappropriately. The wildly over-exaggerated claims of camera effectiveness has given us our ineffective road safety policy: displacement of trafpol instead of what should have been a better trafpol policy (including but not limited to cost recovering trafpol).
The cameras are causing and allowing these inappropriate killer speeds.