Proof that speeding does not kill
Discussion
In 2002 in 30 and 40mph zones in the whole of GB, 58 child pedestrians were killed on the roads and 13,937 were injured. The proportion who were killed was just 0.42%.
1979 research by Ashton and Mackay tells us that the risk of pedestrian death varies with impact speed (approximately) as follows
20mph impact: 10% die
30mph impact: 50% die
40mph impact: 90% die
We also know from official speed surveys that 59% of drivers were exceeding the 30mph speed limit at sample sites.
You might immedately wonder what the average impact speed was to result in 0.42% of deaths. Whatever is was, it was low - well under 5mph - but Ashton and Mackay's graphs don't have enough resolution to give us a speed.
So what intervened and mitigated the effects of speed such that 0.42% died instead of more than 50%? That would be road user response and it is our most precious road safety resource.
But there's much much more. A large number of accidents are minor and result in no injury or are unreported. Let's say that's about 28,000 accidents. Then there are "near misses", where our usual safety systems have failed and emergency response by a road user saves the day and prevents an accident. Research puts the ratio of near misses to accidents at between 5:1 and 30:1.
If we take the lowest ratio, we still have 140,000 incidents involving child pedestrians in incidents in 30 and 40mph zones in 2002. Since we know 59% at sample site exceed the 30mph speed limit we take 59% of 140,000 and we deduce that 82,600 wuld have been exceeding the speed limit in free flowing conditions.
Now subtract ALL the 58 deaths, ascribing them to drivers who would have been speeding. We now have 82,542 drivers involved in incidents with child pedestrians who were probably speeding yet still managed not to kill the child.
Even if 100% of the child pedestrians who died were killed by "speeding drivers" there's still 99.93% of child pedestrians who had incidents with speeding drivers and who did not die as a result.
In summary:
We know for sure from the high number of incidents and the low number of deaths that pre-accident speeding is almost completely useless as a predictor of accident outcomes.
Road user response is at least 500 times more important than pre-incident speed as a predictor of outcomes.
Too much speed enforcement can tend to dull road user response and as such squanders our most precious road safety asset.
Best Regards,
Paul Smith
Safe Speed
www.safespeed.org.uk
1979 research by Ashton and Mackay tells us that the risk of pedestrian death varies with impact speed (approximately) as follows
20mph impact: 10% die
30mph impact: 50% die
40mph impact: 90% die
We also know from official speed surveys that 59% of drivers were exceeding the 30mph speed limit at sample sites.
You might immedately wonder what the average impact speed was to result in 0.42% of deaths. Whatever is was, it was low - well under 5mph - but Ashton and Mackay's graphs don't have enough resolution to give us a speed.
So what intervened and mitigated the effects of speed such that 0.42% died instead of more than 50%? That would be road user response and it is our most precious road safety resource.
But there's much much more. A large number of accidents are minor and result in no injury or are unreported. Let's say that's about 28,000 accidents. Then there are "near misses", where our usual safety systems have failed and emergency response by a road user saves the day and prevents an accident. Research puts the ratio of near misses to accidents at between 5:1 and 30:1.
If we take the lowest ratio, we still have 140,000 incidents involving child pedestrians in incidents in 30 and 40mph zones in 2002. Since we know 59% at sample site exceed the 30mph speed limit we take 59% of 140,000 and we deduce that 82,600 wuld have been exceeding the speed limit in free flowing conditions.
Now subtract ALL the 58 deaths, ascribing them to drivers who would have been speeding. We now have 82,542 drivers involved in incidents with child pedestrians who were probably speeding yet still managed not to kill the child.
Even if 100% of the child pedestrians who died were killed by "speeding drivers" there's still 99.93% of child pedestrians who had incidents with speeding drivers and who did not die as a result.
In summary:
We know for sure from the high number of incidents and the low number of deaths that pre-accident speeding is almost completely useless as a predictor of accident outcomes.
Road user response is at least 500 times more important than pre-incident speed as a predictor of outcomes.
Too much speed enforcement can tend to dull road user response and as such squanders our most precious road safety asset.
Best Regards,
Paul Smith
Safe Speed
www.safespeed.org.uk
safespeed said:
.
Too much speed enforcement can tend to dull road user response and as such squanders our most precious road safety asset.
Best Regards,
Paul Smith
Safe Speed
www.safespeed.org.uk
Why wont they reason with this?
LexSport said:
Paul, excellent piece of work.
Do you have references to Gvmt sources for each and every statistic used?
Thanks. Yes of course. I don't have the urls dead handy, but the casualty figures come from RCGB and the speeding figures come from VSGB (both DfT publications). The death risk in a collision comes from Ashton and Mackay 1979.
The proportions of unreported accidents and near misses are harder to reference and there could be a range of arguments. An American report put near misses to accident at 30:1. AA research in the UK from about 1974 put the ratio of near misses to accidents at 5:1. I don't have copies of either report.
You can make the case well even without reference to the proportions of unreporteds and near misses. 0.42% is still more than 100 times less than half!
Best Regards,
Paul Smith
Safe Speed
www.safespeed.org.uk
LexSport said:
Thanks Paul.
I'd be very interested to see the references when you have them to hand.
casualties figures:
www.dft.gov.uk/stellent/groups/dft_transstats/documents/page/dft_transstats_024382.pdf
I can't find VSGB, but no matter, the same tables appear in TSGB chapter 4, table 4.13:
www.dft.gov.uk/stellent/groups/dft_transstats/documents/page/dft_transstats_025217.pdf
Ashton and Mackay 1979 is referenced in:
www.dft.gov.uk/stellent/groups/dft_rdsafety/documents/page/dft_rdsafety_504644-09.hcsp
(click to expand the first chart on that page: opens this graphic: www.dft.gov.uk/stellent/groups/dft_rdsafety/documents/graphic/dft_rdsafety_504644_ia3efdb975.gif .)
The DfT have somewhat munged the graphs from the Ashton and Mackay originals on:
www.safespeed.org.uk/killspeed.html
Best Regards,
Paul Smith
Safe Speed
www.safespeed.org.uk
There is however comfort here for the anti motorist brigade who are fixed upon one single issue and have no wish to understand the complex interaction
between use of judgement and the reduced reaction times inherent in "dulling of the senses".
The argument would go. If the motorists involved in the 0.42% producing fatalities had been going X% slower at the onset of the incident then at the time of impact the speed reduction would have been such as to in all probability avoid the fatality. I know that statistically that is nonsense, so would they if they wanted to think about it.
But how can you counter the emotional impact and frankly PR factor of 58 child deaths in one year. More than one per week when we have created a culture where someone else is always to blame and SOMEONE HAS GOT TO PAY! Let's face the reality of it, it is a HATE culture, a divisive nanny knows best culture but predominately a culture where fear is introduced into daily life. Where children have to be protected at all costs from a daily pantheon of evil, ranging from priestly paedophiles to all known domestic germs. All the hate and confusion created in society by politically manipulated fears has to have a target. This is clever psychological manipulation carried out by a totally cynical regime, ensuring that there is a focus, indeed whipping up support by carefully leaking more bad press about "EVIL MOTORISTS" and what this caring protective government will do to them on behalf of the people. Displacement activity and a cleverly managed distraction.
You can actually see the manipulation going on here. Under the current and probably sensible and simple system, prior to the introduction of private enterprise law 'enforcement' for private profit, all fines went into a big pot. The pot paid for or towards all aspects of operating the law, including compensation for victims of crime. The key was that fines were supposed to be proportional to the crime committed and the circumstances pertaining. Thus all fines, without reference to the nature of the offence, paid towards all victim compensation without reference to the cause of the damage. Under the new scheme proposed, this will remain the same in broad effect. All that has changed is that this government proposes to publicly identify certain HATE groups to garner popular support for what is actually only a massive increase in the fines tariff to increase revenues to the system. But had they simply applied such a major increase then public resistance may have been felt, particularly if the point had been made that the additional income is necessary to compensate for the bleeding off of substantial sums to pay the profits of the private firms who now enforce increasing sections of the law, for profit. This would not make good publicity for a 'Socialist' government. So what to do...... spin it into just retribution against a HATE group, turn the focus on an enemy who collectively killed 58 children in one year and then want to defend the right to keep on killing children. Of course this cannot be true, this government has "turned away from spin". Peter Mandelson and Alistair Campbell are gone to prove it.
It would take a Maurice Saatchi to find the way to truth when all the government have to do is lift a lazy finger and point to the emotional impact of 58 deaths, more than one per week. Few human beings in the British culture will be truly indifferent to those deaths, what emotive power to tap into!
between use of judgement and the reduced reaction times inherent in "dulling of the senses".
The argument would go. If the motorists involved in the 0.42% producing fatalities had been going X% slower at the onset of the incident then at the time of impact the speed reduction would have been such as to in all probability avoid the fatality. I know that statistically that is nonsense, so would they if they wanted to think about it.
But how can you counter the emotional impact and frankly PR factor of 58 child deaths in one year. More than one per week when we have created a culture where someone else is always to blame and SOMEONE HAS GOT TO PAY! Let's face the reality of it, it is a HATE culture, a divisive nanny knows best culture but predominately a culture where fear is introduced into daily life. Where children have to be protected at all costs from a daily pantheon of evil, ranging from priestly paedophiles to all known domestic germs. All the hate and confusion created in society by politically manipulated fears has to have a target. This is clever psychological manipulation carried out by a totally cynical regime, ensuring that there is a focus, indeed whipping up support by carefully leaking more bad press about "EVIL MOTORISTS" and what this caring protective government will do to them on behalf of the people. Displacement activity and a cleverly managed distraction.
You can actually see the manipulation going on here. Under the current and probably sensible and simple system, prior to the introduction of private enterprise law 'enforcement' for private profit, all fines went into a big pot. The pot paid for or towards all aspects of operating the law, including compensation for victims of crime. The key was that fines were supposed to be proportional to the crime committed and the circumstances pertaining. Thus all fines, without reference to the nature of the offence, paid towards all victim compensation without reference to the cause of the damage. Under the new scheme proposed, this will remain the same in broad effect. All that has changed is that this government proposes to publicly identify certain HATE groups to garner popular support for what is actually only a massive increase in the fines tariff to increase revenues to the system. But had they simply applied such a major increase then public resistance may have been felt, particularly if the point had been made that the additional income is necessary to compensate for the bleeding off of substantial sums to pay the profits of the private firms who now enforce increasing sections of the law, for profit. This would not make good publicity for a 'Socialist' government. So what to do...... spin it into just retribution against a HATE group, turn the focus on an enemy who collectively killed 58 children in one year and then want to defend the right to keep on killing children. Of course this cannot be true, this government has "turned away from spin". Peter Mandelson and Alistair Campbell are gone to prove it.
It would take a Maurice Saatchi to find the way to truth when all the government have to do is lift a lazy finger and point to the emotional impact of 58 deaths, more than one per week. Few human beings in the British culture will be truly indifferent to those deaths, what emotive power to tap into!
V12 Bob - you've got it exactly right.
I just add that I am constantly irritated by the easily suggestible who buy into what this Government and its lackeys are up to.
The way I see it, we have:
1. Those who push through this brainwashing knowing it not to be true, but marketing the initiative as if it's "for the good" and
2. The "useful idiots" who truly believe it.
I just add that I am constantly irritated by the easily suggestible who buy into what this Government and its lackeys are up to.
The way I see it, we have:
1. Those who push through this brainwashing knowing it not to be true, but marketing the initiative as if it's "for the good" and
2. The "useful idiots" who truly believe it.
A slight issue: Pc pervades all aspects; Its invaded your post a little V12 Bob.
" an enemy who collectively killed 58 children "....who says who killed who?
The point here is an automatic assumption that its the driver who "killed" the child, rather than the child who killed the child by running out without STOP, LOOK, LISTEN.
Just my 2p's worth.(otherwise spot on mate)
" an enemy who collectively killed 58 children "....who says who killed who?
The point here is an automatic assumption that its the driver who "killed" the child, rather than the child who killed the child by running out without STOP, LOOK, LISTEN.
Just my 2p's worth.(otherwise spot on mate)
What we should be having a mature debate about is:
1. How can we effectively reduce road causalities to a minimum whilst maintaining a viable transport system?
2. The hard one no politician can ever afford to utter: Living carries risks. What in practical terms is the minimum casualty rate that has to be accepted in the realistic cost/benefit equation?
1. How can we effectively reduce road causalities to a minimum whilst maintaining a viable transport system?
2. The hard one no politician can ever afford to utter: Living carries risks. What in practical terms is the minimum casualty rate that has to be accepted in the realistic cost/benefit equation?
Good stuff, Bob. Ultimately the govt want us out of our private transport and onto public transport, that is the long term goal, they encourage and support 'hate' groups like Safety Partnerships, Brake, T2000, and the multitude of other 'victim support' groups that spring up almost daily.
The only weapon we have as far as I can see is to do as Paul Smith is doing, get the media on side with proof of the lies and spin produced by the 'Partnerships' etc and hope the public see through it all.
The only weapon we have as far as I can see is to do as Paul Smith is doing, get the media on side with proof of the lies and spin produced by the 'Partnerships' etc and hope the public see through it all.
Bob, road casualties were reducing before the onset of revenue cameras, due in the main, I should think, by the manufacture of cars with ever more sophisticated safety features.
The release onto the roads of better drivers, by means of a better focussed driving test would be a good start (together with the policically dangerous scrapping of speed cameras).
The release onto the roads of better drivers, by means of a better focussed driving test would be a good start (together with the policically dangerous scrapping of speed cameras).
V12Bob said:
2. The hard one no politician can ever afford to utter: Living carries risks. What in practical terms is the minimum casualty rate that has to be accepted in the realistic cost/benefit equation?
How true.
If I remember correctly, they decided that a life was worth about £1m on the railways by calculating the cost of installing a safety system (was it something like ATPS?) and how many lives it would save. Then they decided it wasn't worth it and took it no further.
I wonder what similar calculations are made behind the scenes in government, the fall back position being more scameras.
jmr59 said:
SS, those stats are nonsense, until you can show the speeds at which the accidents occurred, rather than the speed people were doing where there was no acciedent.
Not true. Three main reasons:
1) Camera based road safety depends on the speed limit. Obviously these figures show that drivers have slowed down way below 30mph on average. Cameras can't make them significantly slower when they are slower than the limit already.
2) The figures prove that drivers slow in areas of danger and brake before impact. These are vital road safety behaviours at least 500 times more important than free travelling speed.
3) You may not have realised that an estimated 80,000 plus drivers who would have been speeding in free flowing conditions (i.e. where the cameras enforce) used their responses to avoid causing a fatality. Just 58 failed. We must look at improving the performance of the 58, not interferring with the performance of the 80,000.
Best Regards,
Paul Smith
Safe Speed
www.safespeed.org.uk
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