azekeil

That's a US billion. English billion is 10^12.

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growf.livejournal.com

Actually, 10^9 is an everywhere billion now - but you're quite right. We used to call 10^9 a milliard.

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racinghippo.livejournal.com

I'm afraid the Homicidal Psycho Jungle Cat is right. A "British" billion is a million million.
However, it is now deprecated, and we have admitted that it is one of the very, very few words that Americans have got right and we've got wrong :P

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gerald_duck

We didn't get it wrong; billion = million million, trillion = million million million, etc. made good sense.

We also had a perfectly acceptable word for 10⁹: 'milliard', which has now fallen into disuse.

I don't think we've made any admission that the Americans were right, merely that, in a matter where the confusion could be so utterly disastrous, pragmatism necessitated giving way to them.

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racinghippo.livejournal.com

Well said, and thank-you Mr Duck.
My belief in the supremacy of the Queen's English is restored, my Upper Lip stiffened.

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yaruar.livejournal.com

I think the stats for fatalities are probably skewed in comparison to cars because of the greater chance for a fatality when in an accident on a bike. would be interesting to see the comparision between accident figures and the distribution of injuries...

anyway percentage chance is right.

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gerald_duck

[gets home, digs out Transport Planning and Traffic Engineering from his library]

In 1993, there were 3814 fatalities on British roads, and 306,020 casualties - i.e. 1 fatality for every 80 casualties.

For motorcyclists and motorcycle passengers only, there were 427 fatalities and 25,094 casualties, 1 fatality for every 59 casualties.

So yes, injuries are more likely to be fatal on a bike, but by a margin that pales into insignificance compared with the fourtyfold increased risk of death.

I'm afraid there's a reason why people in the medical profession refer to motorcyclists as "donors". To put things in perspective another way: you know how few other motorcyclists you see on the roads, well bear in mind that 1 in 9 people who die on the roads were on a motorcycle at the time!

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ciphergoth.livejournal.com

"How to Lie With Statistics" has an illustrative tale of what appears to be an inexplicable polio epidemic at a particular place and time co-inciding with an *improvement* in medical care. This turns out to be not because the incidence of polio has increased, but because the doctors are successfully diagnosing more cases.

Moral: if you can, compare fatalities, they're much more less affected by reporting bias.

I don't think it's "skew" - it accurately reflects one of the ways in which motorbikes are more dangerous.

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growf.livejournal.com

You could of course have just divided 123 by 2.9 in the first place to work out motorcycle fatalities are 42 times more likely.

However, motorcyclists do kill fewer people than motorists - though that's probably of very little comfort.

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123/2.9 = 42.41, all the miles/km/years stuff is irrelevant, since the original figures are already in the same units, so however many miles you do, even just one, you are 42 times more likely to be killed on a bike than a car.

My dad (who rode a motorcycle as a secure courier for GCHQ after he left the RAF, and therefore had to carry a pistol with him) would not let any of us (his three sons) ride a motorbike because he'd seen how dangerous they were (I'm still thinking about it, neither of my brothers rides m'bikes either)

Erm, "English" billions are a million million, but everyone nowadays uses US thousand millions for billions so that bit is ok.

Your math fails in that it would imply that if you drove one billion miles you'd die 123 times on a bike. It's like saying that the chance of winning the lottery is 1 in 14 million so if you buy one ticket every week for 14 million weeks you will win, which isn't true.

However you are right in that your chance of dying is 42 times greater on a bike than a car for equal distances travelled.

Also note that a surprisingly large percentage of motorcycle accidents (not necessarily lethal ones) happen in the first half hour of owning a bike that is new to you (not being used to the power, trying it out to see how fast it will go, getting it wrong on corners etc.) so that's the time to be especially careful.

And since 75% of accidents happen within a mile of home, move out!

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The statistics refer to fatalities only.

But I think the grounds for the statistics are true - you'd be very likely to die if somehow you managed to ride a million million miles on a motorbike, never mind fuel etc!

I did actually take VERY careful consideration before I chose to take up biking because my dad nearly died in a motorcycle accident before I was born.

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not sure I understand your reply old chap!

Yes, fatalities only, and I couldn't play the lottery for 14 million weeks either without getting very very old!

It's dangerous, it's part of the fun. If you want safe, drive a volvo, but only on your own property and never more than five miles an hour, and take out asteroid insurance!

Some might say bikers die younger but have lived ten times as much as a car driver ... others may disagree!

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growf.livejournal.com

Tell you what, how about next time you email us all first for proofreading?

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Ok, 'was', not 'is'. But then that's a govt billion...

Right - well the DfT have completely fucked their website up so I can't get to the data I wanted, but I know that for pedal cycles, the mean time between serious injuries (not death) is just shy of four millenia.

That said, I was speaking to one of the Venerable Voices Of Cycling on Sunday, who also used to be a keen biker, and he noted he didn't know anyone who'd not fallen off their mobi's. Even then, I don't believe that motorcycling really kills 1 in 10 bikers.

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The maths are wrong, it's more that for each kilometre covered you have a 123/1,000,000,000 chance of dying. Or more exactly, if 1,000,000 bikers each rode 1,000 miles a year, 123 of them would die in a motorbike accident each year (and probably many more hundreds would die of heart attacks, strokes, cancer etc.)

It used to be said that the average length of time between serious injury of a pedal cyclist in central london was 18 months. Which doesn't stop any particular cyclist cycling for 40 years without a scratch, but in the few months I cycled I had doors opened in front of me, a petrol tanker try to run me over, and a pedal snap off while I was trying to get away quickly from the lights, and the only major injury I got was hitting a patch of gravel and tearing all the skin off both knees ... however that kept me off the bike for weeks so that probably counts!

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So the maths would be (123 / 1,000,000,000) ^ 800,000?

Windows Calculator won't do it. I'll maybe fiddle later.

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But, yes, you're pretty much right, if you are an "average cyclist".

But it's hard to measure because I don't know how many billion miles cars and m'cycles do. There are roughly 20 million cars and each car does roughly 25,000km a year, so that's 500 billion road miles, times 2.9 = 1450 deaths a year in cars. I have no statistics for motor cycles, but if there were the same number of deaths and bikes did the same average distance, that would equate to about half a million motorbikes ... anyone know the correct number?

If you do the miles/klicks you say, then odds are about what you say ... I'm just saying that these are odds, so you could do a gazillion kilometres and not die, or just ten kilometres and be squashed by a truck (please god, no) and yes, your odds of dieing on a bike are 42 times higher than in a car if you do the same mileage, on average.

Arghhh, my brain, she is melting! I'm going to go lie down in a dark room now ...

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gerald_duck

Er... no - that would be the chance of dying every kilometre if you did 800,000km. Quite apart from the fact that as a non-vampire (I hope?) you don't keep going after you die, it's understandable that the Windows calculator failed to cope - the answer's somewhere around 10^-5,530,000!

The expression you want (as I mentioned further down) is: 1 - (1 - 123/1,000,000,000)^800,000.

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Maybe not sensible bikers. There are idiots out there, but still. Enough to make me sweat.

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And that's not how I'm spelt :p

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*laughs* Okay, fixed now :)

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racinghippo.livejournal.com

When I was in the last years of school, and had friends/friends' siblings who drove/rode, I did a simple comparison:

People I know who have been injured in car accidents: 0
People I know who have been injured in bike accidents: 1

And put it down to the injured person being a twat (because he was).

Then in July 1981 I added another statistic to the list:

Close friends that have been fatally injured in a bike accident that wasn't their fault: 1

I can understand the attraction of bikes (I love to tinker), and will willingly risk life and limb in countless other dangerous/fast pursuits, but I lost all interest in bikes the day that Adrian died.

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aeia.livejournal.com

What about number of people killed crossing the road. People killed due to alcohol consumption, smoking etc etc..

OK, so bikes are more dangerous than cars, but they're also much more FUN imho anyway. I have a car for practical purposes, my bike is for fun.

Plus those stats must contain lots of darft teenagers on mopeds and couriers, remove those two and I'm sure the stats drop some.

Life's often a compromise between safe but dull or unsafe but exciting. Not just in physical but mental risk. It's all a balance and a bloody hard one to get right (if we ever do!).

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ciphergoth.livejournal.com

Life's often a compromise between safe but dull or unsafe but exciting.

I think this is one of the greatest and most dangerous fallacies of our time. I don't believe you have to significantly compromise your safety to have something close to the best time it's possible to have. There are certain pleasures you'll miss out on if you avoid very unsafe activities, but I don't think they are vastly better than the safer pleasures that remain.

One example of my idea of a good time is a sadomasochistic orgy on drugs, an activity entirely compatible with my health-risk-averse attitude to life.

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Road Traffic Statistics for Great Britain: 2002
http://www.dft.gov.uk/stellent/groups/dft_transstats/documents/page/dft_transstats_023319.hcsp
(for distances)

Road Casualties in Great Britain Main Results: 2002
http://www.dft.gov.uk/stellent/groups/dft_transstats/documents/page/dft_transstats_022247.hcsp
(for deaths)

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Hrm. I think I'll stick to pedalling. It seems to be the only form of transport that puts your life expectation *up*.

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feanelwa.livejournal.com

Except walking to the supermarket. If you never went, your life expectation would be 53 days...

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sarah-mum.livejournal.com

Here's another stat for you.
Number of times I've ridden a motorbike in over 17 years of holding a driving licence = 0

Anyone want to help me with correcting this?

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gerald_duck

"40 times as dangerous per person-mile travelled as the next most dangerous form of transport" is my rule of thumb on how dangerous motorbikes are - I've had figures supporting that rule of thumb from various books on risk, on traffic management, etc.

Given the 123 fatalities per 1e9 kilometres figure, I make the chances of dying in 800,000km about 9.4% .

The discrepancy from your 9.84% is because 1-P(dying in n km) ≡ (1-P(dying in 1km))ⁿ - this gives almost the same answer as you got for low n, but the discrepancy grows as you approach n=8.1 million.

Yes, the facts are scary. They only go largely unnoticed because so few people ride motorbikes, and because people travel less far on motorbikes than in cars. I've always been tempted by the idea of a motorbike, and safety is the principal reason I've not indulged (poor fuel tank range and hardly any luggage space are another two I can think of right now).

For me, for everyday transport, a motorbike is out of the question. I do 55,000km a year. I hope to be driving for at least another 40 years, so that's two and a quarter million km I'd have to survive. On a motorbike, the odds of survival would be only 76%, in a car 99.3% .

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Ah, yes, I've just suffered a terrible flashback of A-level maths. God help me.

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jessie-pup.livejournal.com

Interesting stats although ultimately it's up to your riding to how likely it is to you having a fatal accident. Sitting on what's an amounts to an engine on wheels at high velocities is never going to be safe. Riding motorbikes is one of my greatest pleasures and I'd never give it up because it's not the same safety record as driving a cage. Don't be an average rider and the average stats needn't apply :)

(surely it's worth it just for humiliating drivers of boyed up cars!) :D

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cybersofa.livejournal.com

> Don't be an average rider

Well said. Advanced training == way to go, IMHO.

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gashinryu.livejournal.com

Don't die.

We're not done with you yet. :-)

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phrixus-nyx.livejournal.com

Very interesting - I bet it doesn't tell you what percentage of those bike fatalities were caused by car drivers not looking where they were going?

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gerald_duck

Well, quite. It doesn't matter if you die, of course, provided it's someone else's fault.

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cryx

and remember you can be the safest driver in the world, but you are liable to come of worse if a foolish car driver hits you.

See when my brothers face was smashed and best mate killed, when a car failed to give way at a junction.

see when a lady tried to drive onto a roundabout *through* my old supervisor. She only stopped halfway on the roundabout with my supervisor on her bonnet screaming "for god's sake woman, STOP!!" She had failed to notice the grinding sounds as she pushed the fallen motorbike forward, and her excuse was that she was late for an interview!!!

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