New research on relative risks of different modes.

Mike Sales
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New research on relative risks of different modes.

Postby Mike Sales » 6 Dec 2012, 8:32pm

Road.CC reports a new study.

http://road.cc/content/news/71717-govt-stats-over-state-risks-cycling-says-new-research-its-pedestrians-young-male

Cycling is not as risky as official statistics suggest says new research - in fact, for young men it is safer than driving.


According to the research by a team from the Department of Epidemiology and Public Health at University College London (UCL), official statistics consistently overstate the risks involved with cycling and underestimate those associated with walking and driving - their most eye-catching findings is that cycling is a safer than driving for young men between 17-20 years old.


And for those they share the road with, I dare say.

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squeaker
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Re: New research on relative risks of different modes.

Postby squeaker » 6 Dec 2012, 11:34pm

"42"

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horizon
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Re: New research on relative risks of different modes.

Postby horizon » 6 Dec 2012, 11:59pm

This is slightly off topic but I picked out the following quote:

However time spent travelling per day - on average an hour - is pretty much the same, no matter what mode of transport people use.

If it means what I take it to mean, it implies that every form of faster (and usually environmentally disastrous) form of travel is a complete waste of public money - people still end up travelling one hour per day whether on horseback, Maserati, motorway, train or bike. So much for your new roads programme Mr Osborne (and for HS2).
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher

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Re: New research on relative risks of different modes.

Postby meic » 7 Dec 2012, 12:34am

You say "so much for your new road plan (and HS2)" but that is from our perspective as people.
From his perspective, he can screw so much more out of us if we spend that hour in a car, on a bus, on a train or even on a plane.
Yma o Hyd

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Re: New research on relative risks of different modes.

Postby iviehoff » 7 Dec 2012, 11:06am

horizon wrote:If it means what I take it to mean, it implies that every form of faster (and usually environmentally disastrous) form of travel is a complete waste of public money - people still end up travelling one hour per day whether on horseback, Maserati, motorway, train or bike. So much for your new roads programme Mr Osborne (and for HS2).

If you think about the people in a village with no roads travelling an hour a day on foot/mule and the economic consequences that level of transport connectivity has for them, you will realise that what you just said makes little sense. People may end up travelling similar amounts of time, about an hour a day, but a greater level of transport connectivity gives them much greater possibilities of economic advantage for that hour's travel.

In reality, well-planned improvements in transport connectivity usually present the among the highest cost/benefit ratios of all public spending opportunities, even if you think the environmental costs have been undervalued. Though HS2 is not one of those, it has quite a weak cost/benefit ratio even on the government's own numbers.

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Re: New research on relative risks of different modes.

Postby horizon » 7 Dec 2012, 11:46am

iviehoff wrote:If you think about the people in a village with no roads travelling an hour a day on foot/mule and the economic consequences that level of transport connectivity has for them, you will realise that what you just said makes little sense. People may end up travelling similar amounts of time, about an hour a day, but a greater level of transport connectivity gives them much greater possibilities of economic advantage for that hour's travel.



This is true but like most things it is true only to an extent (as was my post as you suggest). The theory is that if you build a by-pass, people will get to the next town more quickly and thus shorten their journey time. In practice, they increase their mileage back up to the time they previously spent travelling. Hopefully, they will have gained something by going that extra distance but that isn't necessarily the case.

Just to add that this is a huge topic (can of worms?) I have opened so "I'm out" as they say on a well known TV programme. I'd have to argue that the benefits of that extra connectivity are subject to a law of diminishing returns.
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher

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Re: New research on relative risks of different modes.

Postby Si » 7 Dec 2012, 1:42pm

I read a report of the research which made a quote along the lines of : if you cycle for an hour a day for forty years then you have a 1 in 150 chance of being killed while cycling.

Now despite the thrust of this report being that cycling is safer than many think, this particular bit of info seems to somewhat paint cycling as very dangerous!

After all, you you have a 1/2 hour each way ride to work that you do 5 days a week starting at age 20, then very roughly speaking 1 in 200 won't make it to retirement!

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Re: New research on relative risks of different modes.

Postby Ellieb » 7 Dec 2012, 2:21pm

Given it went out at the same time as 'The War on Britain's Roads' I don't really have a problem with putting out counter 'propaganda' . But at the risk of this seeming like an ad hominem attack my sesnse that this is an objective assessment of the situation was dulled by the fact that I managed to guess who one of the co-authors of the research was. It is all a bit tendentious for me

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Re: New research on relative risks of different modes.

Postby Mike Sales » 7 Dec 2012, 2:39pm

Ellieb wrote:Given it went out at the same time as 'The War on Britain's Roads' I don't really have a problem with putting out counter 'propaganda' . But at the risk of this seeming like an ad hominem attack my sesnse that this is an objective assessment of the situation was dulled by the fact that I managed to guess who one of the co-authors of the research was. It is all a bit tendentious for me


"It" was not a TV programme, so did not "go out" at a particular time. (If I have misunderstood your post I apologise.)
Do you mean to say that you expected Wardlaw to be a co author? You are much cleverer than me, in spite of my interest in these matters I did not guess. Do you have any more pertinent criticism of the study than that?

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Re: New research on relative risks of different modes.

Postby Ellieb » 7 Dec 2012, 3:03pm

Let me say again I applaud any attempt to get more people cycling & that given the public as a whole seems to think that getting on a bike = instant death then I agee that the risks of cycling are over-exaggerated by and large.
However, the sad fact is that I did read this and thought "this is the sort of thing Wardlaw might have written" and I was genuinely slightly disappointed to turn to look at the authors and find "Oh....he has."

But even on a casual reading things like trying to take out motorway mileages: One of the points they make is that people generally commute for the same amount of time regardless of mode & that is why they prefer to measure the risk in terms of per hour. Well, an awful lot of people commute on motorways and do so for periods of less than an hour. To try to claim that motorway mileage is solely a sort of 'long duration' travel & should not be compared to cycling I would suggest is a distortion. Likewise they seek to eliminate 'high risk' activities like BMX/sportives etc from the cycling stats on the grounds it isn't transport. I would suggest that a significant source of young male car fatalities isn't 'transport' either. Racing your mates or impressing the girls by doing tricks & stunts accounts for an awful lot of late night accidents. It is using a vehicle to have fun...just like mountain biking.

I could go on, but ultimately for me, this all reads like the researchers set out to find ways to minimize the statistical risk of cycling & funnily enough they achieved it.
EDIT: I also noticed this, which I think is a bit disingenuous.

In the UK, most drivers are middle-aged adults, with almost half being female, while cycling is male-dominated and has traditionally been considered predominantly an activity of youth: 24% of serious casualties among cyclists are <20 y old, compared with 12% of serious casualties among drivers [9]. The increased risk-taking associated with both young age and male sex are well-known and confound comparisons of cycling and driving.


Why use the phrase 'traditionally been considered' ? Is this because cycling isn't actually predominantly an activity of youth? DfT stats show that it is the middle aged who do most miles.

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Re: New research on relative risks of different modes.

Postby Mike Sales » 7 Dec 2012, 6:37pm

Ellieb wrote:Let me say again I applaud any attempt to get more people cycling & that given the public as a whole seems to think that getting on a bike = instant death then I agee that the risks of cycling are over-exaggerated by and large.
However, the sad fact is that I did read this and thought "this is the sort of thing Wardlaw might have written" and I was genuinely slightly disappointed to turn to look at the authors and find "Oh....he has."

But even on a casual reading things like trying to take out motorway mileages: One of the points they make is that people generally commute for the same amount of time regardless of mode & that is why they prefer to measure the risk in terms of per hour. Well, an awful lot of people commute on motorways and do so for periods of less than an hour. To try to claim that motorway mileage is solely a sort of 'long duration' travel & should not be compared to cycling I would suggest is a distortion. Likewise they seek to eliminate 'high risk' activities like BMX/sportives etc from the cycling stats on the grounds it isn't transport. I would suggest that a significant source of young male car fatalities isn't 'transport' either. Racing your mates or impressing the girls by doing tricks & stunts accounts for an awful lot of late night accidents. It is using a vehicle to have fun...just like mountain biking.

I could go on, but ultimately for me, this all reads like the researchers set out to find ways to minimize the statistical risk of cycling & funnily enough they achieved it.
EDIT: I also noticed this, which I think is a bit disingenuous.

In the UK, most drivers are middle-aged adults, with almost half being female, while cycling is male-dominated and has traditionally been considered predominantly an activity of youth: 24% of serious casualties among cyclists are <20 y old, compared with 12% of serious casualties among drivers [9]. The increased risk-taking associated with both young age and male sex are well-known and confound comparisons of cycling and driving.


Why use the phrase 'traditionally been considered' ? Is this because cycling isn't actually predominantly an activity of youth? DfT stats show that it is the middle aged who do most miles.


What I find annoying, and I expect you do to, is the sort of assessment of relative danger which takes no account of exposure to road danger, and no account of quality of exposure. At the extreme you have the Transport Minister who recently claimed that Britain is safer for cycling than the Netherlands, since fewer cyclist die on the road. Different modes do have different exposure to risk, and different types of cyclist do too.
Another extreme of distortion, which I include to make clear my argument, is to compare road and air travel in terms of fatalities per mile. The use patterns of air travel and road travel and the miles per journey in the two modes are so different that deaths per mile is a misleading comparison. Deaths per hour might be more illuminating.
The authors of this study do not claim that it is long distance motorway travel which distorts the understanding of risk, but that any motorway travel, even shorter distance commuting, is at a higher speed, so a figure of accidents per mile gives a different impression to the rate per hour. Since faster roads encourage longer distance commuting (if the limiting factor is time, as it surely is; we only have so many hours in the day) it is mistaken to look at rate per mile when deciding which mode is safer.
You say that cycling is not predominantly an activity of male youth. Do these DfT statistics distinguish where the miles are ridden? Riding on busy urban roads is very different to riding as a sport (or sportif) activity on the country lanes used by club riders. No doubt this confounding factor arises because the most pleasant and safest riding is not in cities.
No doubt some of the damage young drivers do is done when joyriding. How much is done when driving friends for transport reasons, but nevertheless in showing off?
This paper is a much more sophisticated attempt to assess the risks than the vast majority of unsubstantiated assertions. It is open and reasoned in its working. I think it is likely to be closer to the truth than most assessments.
I don't think that the best way to make progress in assessing the risks is to discount others' efforts because you suspect motives. Argument ought to be with the substance of what they say. I'm glad my previous post has encouraged you to do that.

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Re: New research on relative risks of different modes.

Postby Pete Owens » 7 Dec 2012, 11:44pm

What this paper does is put the evidence into context - and for this you need to compare like-with-like.

The distorting factor concerning motorways is that they are by far our safest roads - they account for about half motorist mileage, but no cycling whatsoever. If you are going to compare like with like you need to compare similar journeys. Most cycling consists of short urban trips - so to get an idea of the relative safety of modes you need to compare short urban journeys by one mode with short urban journeys by another.

Including extreme off-road cycling crashes in the transport stats (as the official figures do) makes about as much sense as including winter climbing falls off the north face of Ben Nevis as "pedestrian" casualties, or judging the safety of motoring by analysing crashes at formula 1 races. Also, excluding pedestrian casualties from the figures unless a vehicle involved is a distortion of the figures - most pedestrian casualities are trips and slips - just as most cycle crashes do not involve any other vehicles.

Correcting for demographics is also important. Young males are disproportionately likely to get involved in crashes, whatever mode of transport they happen to be using, yet form a disproportionate proportion of cyclists.

Certainly a teenage youth riding down a single track black run in Llandegla forest is undoubtedly more likely to come a cropper than a middle aged woman driving along the M56. But this tells you absolutely nothing about the relative safety of cycling, walking, driving or catching a bus to the local shops.

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Re: New research on relative risks of different modes.

Postby Ellieb » 8 Dec 2012, 12:22am

Correcting for demographics is also important. Young males are disproportionately likely to get involved in crashes, whatever mode of transport they happen to be using, yet form a disproportionate proportion of cyclists.


Really? Where do you get that stat?

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Re: New research on relative risks of different modes.

Postby Ellieb » 8 Dec 2012, 12:44am

Incidentally, did I imagine it or didn't we discuss some time ago the finding that risky behaviour was not a factor in most cycling accidents & that most accidents are the fault of the driver. I also seem to remember the anxiety expressed that a disproportionate number of women were being killed by lorries in London. Remind me how that all ties in with these findings?

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Re: New research on relative risks of different modes.

Postby snibgo » 8 Dec 2012, 4:22am

It's a fascinating paper. As a male in my fifties, I noticed that my fatality rate (per unit distance) is greater as a pedestrian than as a cyclist, by a fair margin. (Although not, it should be noted, "statistically significant", because the 95% confidence intervals overlap.) The same is true for all age-ranges of men. (And about half of these are statistically significant.)

For women, the opposite is true: they have a lower fatality rate as pedestrians than as cyclists, apart from the over 70s.

Naive conclusion: women should stick to their feet, men to their wheels. But as the confidence intervals suggest, we shouldn't use this as a guiding principle. The numbers are too low to be certain (eg in the 50-59 age range, 8 women cylists died, and that's a very low number to extrapolate to an entire population).

Women walkers and pedestrians have a lower fatality rate than men, with the noticable exception of 17-20 year old cyclists, where women are more than three times as likely to die. (But again, not statistically significant.)

Hospital admissions show a similar picture, but muddier.

Fascinating.