Maths Problem
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nickyboy
Norven Mankey
- Location
- You want hills? We got hills
If 18% of all KSI occur in 1% of the distance covered, 82% must occur in 99% (that's the "vehicles" in your numbers)
So 18/1 = 18
and 82/99 = 0.828
So how much bigger is 18 than 0.828.....18/0.828 = 21.7 times
So your calculation is correct
So 18/1 = 18
and 82/99 = 0.828
So how much bigger is 18 than 0.828.....18/0.828 = 21.7 times
So your calculation is correct
srw
It's a bit more complicated than that...
About the same level of risk - bikes travel considerably slower than cars.
If your sums disagree with the official ones then you're probably screwing something up. The official stats are checked, double-checked and triple-checked by people who are experts. Give us a link and someone can tell you what you've done wrong.
Here's one link, which doesn't give the specific statistics cited: https://www.gov.uk/government/uploa..._data/file/533293/rrcgb-main-results-2015.pdf
If your sums disagree with the official ones then you're probably screwing something up. The official stats are checked, double-checked and triple-checked by people who are experts. Give us a link and someone can tell you what you've done wrong.
Here's one link, which doesn't give the specific statistics cited: https://www.gov.uk/government/uploa..._data/file/533293/rrcgb-main-results-2015.pdf
winjim
Straddle the line, discord and rhyme
[QUOTE 4718171, member: 9609"]Yes, there is lots and lots of different stats to choose from, and obviously any answer is not going to be relevant to everyone, but I was getting annoyed at myself for not being able to work out with confidence an answer to what initially seemed straight forward question.
just based on the 1% & 18% figures, I am curious now where do you get the 13 to 45 bit from ?[/QUOTE]
It's the effect of rounding to whole numbers. 1 can be anything from 0.5 to 1.5 which is a threefold increase. The same goes for 18 which is 17.5 - 18.5 but here the effect is less because the number is bigger to start with.
just based on the 1% & 18% figures, I am curious now where do you get the 13 to 45 bit from ?[/QUOTE]
It's the effect of rounding to whole numbers. 1 can be anything from 0.5 to 1.5 which is a threefold increase. The same goes for 18 which is 17.5 - 18.5 but here the effect is less because the number is bigger to start with.
winjim
Straddle the line, discord and rhyme
The experts will have better data and be aware of the quality of that data. The true figures will not be exactly 8% or 1% or 18%, that's just simplification for the press release. The true figures will be a range, taking account of the uncertainty inherent in every stage of the process.
srw
It's a bit more complicated than that...
And (I may have mentioned this once or twice on this forum) the stats for the number of miles cycled are currently hugely uncertain, because two different ways of gathering those stats differ wildly.
@User9609's question isn't a simple maths problem. It's a difficult question of which measure of risk is best for which circumstance, which dataset is the right one to use and so on.
But whichever way you cut the numbers, you come to the conclusion that Britain's roads are pretty safe for all road users and still getting safer on the back of decades of improved safety, and that cycling isn't, by a long way, the riskiest way of using them. The least safe is motorcycling.
- Location
- Egham
Killed or Seriously Injured
nickyboy
Norven Mankey
- Location
- You want hills? We got hills
srw
It's a bit more complicated than that...
More on the SI part of a KSI:
"An injury for which a person is detained in hospital as an 'in- patient', injury or any of the following injuries whether or not they are detained in hospital: fractures, concussion, internal injuries, crushings, burns (excluding friction burns), severe cuts, severe general shock requiring medical treatment and injuries causing death 30 or more days after the accident. An injured casualty is recorded as seriously or slightly injured by the police on the basis of information available within a short time of the accident. This generally will not reflect the results of a medical examination, but may be influenced according to whether the casualty is hospitalised or not. Hospitalisation procedures will vary regionally."
https://www.publications.parliament.uk/pa/cm200708/cmselect/cmtran/460/46004.htm
That includes quite a lot of things which are a very long way from life-threatening, and potentially quite a lot which won't result in material pain and suffering, or time off work. It also includes minor fractures and minor concussions of the sort cyclists are quite exposed to.
I have a hunch (and it is only a hunch, and not one I'd know how to evidence) that the serious injury statistics, especially for cyclists, are quite inflated. First because I suspect the police err on the side of caution, especially where vulnerable road users are concerned, and second because while Labour's entirely laudable 4-hour target for admissions from A&E was still realistic the easy way for hospitals to meet it was to admit people who didn't really need admission.
That second, by the way, isn't a conspiracy theory - it actually happened to someone I know well. After being knocked off her bike and taken to A&E the doctors didn't get around to her, having a number of more urgent cases to attend to. The hospital preferred to "admit" her to a ward (to sit on the chair by the side of the made-up bed) rather than risk breaking their A&E target.
"An injury for which a person is detained in hospital as an 'in- patient', injury or any of the following injuries whether or not they are detained in hospital: fractures, concussion, internal injuries, crushings, burns (excluding friction burns), severe cuts, severe general shock requiring medical treatment and injuries causing death 30 or more days after the accident. An injured casualty is recorded as seriously or slightly injured by the police on the basis of information available within a short time of the accident. This generally will not reflect the results of a medical examination, but may be influenced according to whether the casualty is hospitalised or not. Hospitalisation procedures will vary regionally."
https://www.publications.parliament.uk/pa/cm200708/cmselect/cmtran/460/46004.htm
That includes quite a lot of things which are a very long way from life-threatening, and potentially quite a lot which won't result in material pain and suffering, or time off work. It also includes minor fractures and minor concussions of the sort cyclists are quite exposed to.
I have a hunch (and it is only a hunch, and not one I'd know how to evidence) that the serious injury statistics, especially for cyclists, are quite inflated. First because I suspect the police err on the side of caution, especially where vulnerable road users are concerned, and second because while Labour's entirely laudable 4-hour target for admissions from A&E was still realistic the easy way for hospitals to meet it was to admit people who didn't really need admission.
That second, by the way, isn't a conspiracy theory - it actually happened to someone I know well. After being knocked off her bike and taken to A&E the doctors didn't get around to her, having a number of more urgent cases to attend to. The hospital preferred to "admit" her to a ward (to sit on the chair by the side of the made-up bed) rather than risk breaking their A&E target.
srw
It's a bit more complicated than that...
...or indeed someone who has an ounce of knowledge about statistics, risk and cycling. And there are a lot of them around on this forum.I hope @User9609 has learned a valuable lesson here
Never ask a "risk" question when there's a chance someone from the insurance industry is around
byegad
Legendary Member
- Location
- NE England
I've typed this before, but it's kind of relevant.
Some years ago I was tidying the shed. I pulled on a pedal which was tied to its mate and hung over a hook. The other pedal came free of the hook at tome speed and smacked me inbetween the eyes, just over my glasses. Within seconds I couldn't see, as both eyes were full of blood from the cut. Lady Byegad transported to hospital where they cleaned me up and superglued the cut.
That's when the fun started.
Nurse, 'How did the accident happen'
Me. 'I pulled on pedal in the shed and it the other one came away and smacked me in the forehead.'
Nurse, 'OK, a cycling accident.'
Me, 'No, it happened in the shed and the pedal wasn't even attached to a bike.'
More of the same ensued, until a senior nurse turned up and made an executive decision that it was a cycling accident.
I got very angry and also got nowhere on this. So back in that year at least one recorded cycling accident wasn't! My final appeal that had I hit my head with a ski, would she record it as a skiing accident (in NE England in July) was duly ignored.
Some years ago I was tidying the shed. I pulled on a pedal which was tied to its mate and hung over a hook. The other pedal came free of the hook at tome speed and smacked me inbetween the eyes, just over my glasses. Within seconds I couldn't see, as both eyes were full of blood from the cut. Lady Byegad transported to hospital where they cleaned me up and superglued the cut.
That's when the fun started.
Nurse, 'How did the accident happen'
Me. 'I pulled on pedal in the shed and it the other one came away and smacked me in the forehead.'
Nurse, 'OK, a cycling accident.'
Me, 'No, it happened in the shed and the pedal wasn't even attached to a bike.'
More of the same ensued, until a senior nurse turned up and made an executive decision that it was a cycling accident.
I got very angry and also got nowhere on this. So back in that year at least one recorded cycling accident wasn't! My final appeal that had I hit my head with a ski, would she record it as a skiing accident (in NE England in July) was duly ignored.
srw
It's a bit more complicated than that...
[QUOTE 4718363, member: 9609"]in nearly any subject you will find experts with very different opinions, so which ones do you believe? they always need to be distrusted as they nearly always have their own agendas. And as or .gov experts, I certainly wouldn't believe any thing coming out of that lot.[/QUOTE]
And that, in three sentences, expresses the challenge facing the world. For whatever reason a whole load of people distrust all expertise, and go on with their next breath to say that they don't.
If you'd like to expose your own source data and workings, and display your own qualifications, in the way in which the government's statistical service that you deride does, feel free. Until then it's frankly not worth carrying on the discussion.
And that, in three sentences, expresses the challenge facing the world. For whatever reason a whole load of people distrust all expertise, and go on with their next breath to say that they don't.
If you'd like to expose your own source data and workings, and display your own qualifications, in the way in which the government's statistical service that you deride does, feel free. Until then it's frankly not worth carrying on the discussion.
Tin Pot
Guru
[QUOTE 4718363, member: 9609"]in nearly any subject you will find experts with very different opinions, so which ones do you believe? [/QUOTE]
The one that has the most logical train of thought supported by the best evidence.
And you should not believe anyone, you should decide to accept a worldview with a degree of trust commensurate with your own understanding of the subject and the degree of rationality and evidence in the point of view.
It's simple really, but people just don't want to think - they just want to know who to follow.
The one that has the most logical train of thought supported by the best evidence.
And you should not believe anyone, you should decide to accept a worldview with a degree of trust commensurate with your own understanding of the subject and the degree of rationality and evidence in the point of view.
It's simple really, but people just don't want to think - they just want to know who to follow.
