I’ve got a bike you can ride it if you like

February 7th, 2009 by Ben Goldacre in bad science | 72 Comments »

The Guardian,
Saturday February 7 2009
Ben Goldacre

Like a lot of people who spend their time thinking about evidence and risk, I’ve always fantasised that the insurance industry must possess a vast repository of useful data: the experience of centuries, carefully tabulated by actuaries into secret commercial databases containing a truth about human behaviour and risk which most epidemiologists and social scientists would kill for.

Here for example is the insurance company LV, who have managed to get their important road safety data analysis onto GMTV.

“Mounting financial pressures have led to a surge in inexperienced cyclists taking to the roads,”say LV in their press release: “resulting in a 29% increase in road accidents involving cyclists in the past six months.” It’s topical, it involves death and fear, it’s dressed in the cloak of statistical authority: this is totally going on the telly.

The first thing to note is that LV were comparing accidents in the 6 months leading up to November 2008 against accidents in the 6 months prior to that. What these insurance geniuses have failed to account for here, we might reasonably suspect, is the well-documented seasonal variation in road traffic incidents, since fewer people cycle in winter. I shall not be buying shares in this insurance company.

But better than that, LV have created a small anecdotal window into how wrong survey data can be, by giving us figures that we can compare directly against those that were created with other, probably better methods.

LV paid YouGov to sample 2,193 adults in November 2008, using an online questionnaire. They start by announcing that 43% of adults cycle, which sounds rather high to me. The General Household Survey is produced by the Office of National Statistics. It doggedly interviews all the adults in a random sample of 13,000 addresses, face to face, asking them a huge number of questions in great detail. The latest GHS reckons that 19% have cycled once in the past year, and 9% in the past 4 weeks. So YouGov and LV Insurance with their online questionnaire are disagreeing by a factor of 4 already.

“Of these,” LV go on: “11 per cent have been involved in an accident, 7 per cent of these took place in the last six months = 150,434 accidents.” We will politely brush over the fact that trivial accidents from the very recent past may be more memorable in a single point survey than older ones, and move to the published accident figures from the Department for Transport (whose website has contained not a single use of the word “snow” this week, rather brilliantly).

There were, according to the most recent figures from DfT, 16,230 accidents in the year from October 2007 to September 2008, so YouGovs’ online questionnaire disagrees this time by a factor of 10. You might speculate that DfT data is prone to under-reporting, and I would agree, but I trust this imperfect data more than I trust the opinion of a PR person who misses barn-door seasonal variation and seriously reckons half of you cycle. Also, most of those accidents reported to the DfT were themselves minor.

God I’m boring. Meanwhile the Cyclists Touring Club, who certainly sound like a dapper bunch, have collected data which shows a 91% increase in cycling in London since 2000. Regardless of how you like that figure, we can also go back through the historical DfT tables which show that far from their dramatic increase in accidents, there was in fact a 1% rise comparing the most recent quarter, July to September 2008, with the same quarter in 2007. In case you think this is just noise – and I share your caution – when compared against the average of 1994-1998, by DfT data, bicycle accidents have fallen by 33%.

So it seems accidents have gradually gone down by a third over ten years, but LV insurance and YouGov – using something my colleague Charlton Brooker has helpfully termed “PR-reviewed scientific evidence” – say accidents have gone up by a third in just six months, using data that forgets to account for the usual seasonal variation, and seems to get the prevalence of both cycling and accidents wrong, by an order of magnitude. Most importantly, this gets on the telly, with a nice puff for the LV brand, despite the fact that almost everything I have told you was spelled out to GMTV, by the boys and girls in tweed at the CTC, before it ever went to air.

Once again, there is nothing complicated here, and I will not be charging for courses, vitamin pills, or secret lifestyle programmes: eat fruit and veg, avoid excess alcohol and cigarettes, ride your bike to work, and ignore everything you see in the media.

Please send your bad science to ben@badscience.net

LV’s Press Release

ROAD USERS WARNED OVER INEXPERIENCED CYCLISTS

Mounting financial pressures have led to a surge in inexperienced cyclists taking to the roads, resulting in a 29% increase in road accidents involving cyclists in the past six months1.

New research from car insurer LV= reveals that one in 20 Brits2 have got on their bikes in the past 12 months in an attempt to cut costs. Yet the findings show that this has caused a surge in accidents with 150,0003 cyclists saying they have been involved in a road accident in the last six months.

A lack of formal training may be one of the causes of this problem, with more than half (52 per cent) of cyclists admitting they have never read the Highway Code’s advice for cyclists and just 42 per cent have taken a cycling proficiency course.

This is illustrated by British cyclists’ ignorance of basic road rules – with a quarter (24 per cent) unable to identify a ‘cyclists prohibited’ sign and one in five admitting to night cycling without working lights.

Other common errors include cycling on the pavement (41 per cent) – which is currently illegal, and failing to wear a safety helmet (42 per cent) which can drastically reduce the risk of injury.

In the past year one in three cyclists have cycled the wrong way up a one way street, and one in 20 (six per cent) admitted to cycling under the influence of drugs or alcohol and a similar number confessed to using a mobile phone whilst cycling.

With many thousands of inexperienced cyclists taking to the roads, motorists and other road users need to be extra vigilant to avoid collisions and cyclists need to ensure they are aware of and stick to the rules of the roads.

The majority of Brits (64 per cent) would like to see adult cycling proficiency tests become compulsory so LV= is calling on the Government and local councils to increase the availability of training for cyclists.

Emma Holyer, Spokesperson for LV= Car Insurance, said:

“Cycling is a cheap and enjoyable way to get from A to B and great exercise at the same time but it’s essential that cyclists are fully equipped to deal with the busy British roads to ensure their own safety and that of other road users.

“If cycling training was compulsory, and cyclists were better equipped to follow the rules of the roads we believe motorists, pedestrians and cyclists themselves would all benefit from fewer accidents and a safer environment on the road.”

For more information, log on to www.lv.com.

– ends –

Emma Holyer / LV= Press Office

Notes to editors
All figures, unless otherwise stated, are from YouGov Plc. Total sample size was 2,193 adults. Fieldwork was undertaken between 18th – 20th November 2008. The survey was carried out online. The figures have been weighted and are representative of all GB adults (aged 18+).

1. Of the 45,434,897 UK adult population (2001 census), 43 per cent cycle. Of these, 11 per cent have been involved in an accident, 7 per cent of these took place in the last six months = 150,434 accidents. In the year six months previously 4 per cent of all accidents took place = 85,962 accidents. There has therefore been a 29 per cent increase in accidents.

2. Of the UK adult population (45,434,897) 6 per cent have started cycling in the last 12 months = 2.7 million cyclists

3. 150,434 accidents in the last six months (see above for full methodology)


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72 Responses



  1. pseudomonas said,

    February 9, 2009 at 5:45 pm

    Skizz: I suspect that drivers need to be skilled as well to avoid collisions. Thing is, a minor everyday bump that between two cars would be a little scratch on someone’s bodywork, maybe re-aligning a wing-mirror, can be rather more unpleasant between a car and a bike.

  2. NorthernBoy said,

    February 9, 2009 at 6:17 pm

    On the subject of there being a war between cyclists and motorists, it does sometimes seem that way. TFL has recently started a trial to see the effect of allowing motorcyclists to use their bus lanes, alongside cyclists, buses and taxis. This is following a pilot trial that strongly suggested that deaths and serious injuries would be reduced in ALL groups concerned (tht is, in each group individually, not only overall).

    Despite this being a trial, to more fully assess the effects, and despite earlier evidence being that it will make life safer for cyclists, there has been an organised campaign by cycling groups to protest the move. I can’t really see what can have motivated this other than antipathy towards people with private motorised transport.

    Motorbike groups have responded by asking bikers to follow a voluntary code of conduct that will stop cyclists feeling harassed, endangered, or inconvenienced by the change.

  3. Robert Carnegie said,

    February 9, 2009 at 6:36 pm

    My guess where this came from: someone in the office said “I bet more people are riding bicycles now because of the credit crunch, I bet they’re not very good at it,” and the rest was made up to fit that. And presumably there’s something about insuring your bike for theft or for injury, although that may be only a matter of listing it on contents, for both.

    Be careful out there!

  4. carl parisien said,

    February 9, 2009 at 10:55 pm

    I agree Robert. This seems rather arcane. Robert Carl Parisien

  5. jsymes said,

    February 10, 2009 at 1:00 am

    Dr Goldacre concludes:…”and ignore everything you see in the media.” And as the wise Professor Sir Muir Gray might add: “…including here”.

  6. Psychedelia Smith said,

    February 10, 2009 at 12:13 pm

    Has anyone got LV Insurance’s number? I just came off my bike this morning…

    ‘Tis a bad omen, I tell thee!

  7. leob said,

    February 10, 2009 at 9:00 pm

    Can anyone find any more info on the poll/results? As a pollster, I could have some fun picking it apart…

  8. Pro-reason said,

    February 11, 2009 at 7:10 am

    Howfar:

    “Drivers don’t kill anyone collectively, any more than cyclists collectively die.”

    That is utterly stupid and meaningless.

    “Cycle safely”

    We’ve already established that I cycle safely, shit-for-brains.

    “and obey the rules of the road, they are there for a reason.”

    They are there to stop cars killing people. They are then mindlessly applied (by motorists) to people not in vehicles. If it’s not appropriate for me to walk/cycle/skate in the road in a given situation, I’ll do it on the pavement. The fact that it’s virtually never appropriate for a car to do the same is not my problem.

  9. NorthernBoy said,

    February 11, 2009 at 10:01 am

    Pro-reason, your infantile insults only emphasise the points others have made against cyclists like you. If you cycle as you say, then you are cycling selfishly and illegally. Although this does not remove your right to whine like a bitch, it does however mean that no-one is really going to listen to it when you do.

    People like you give cyclists a bad name, and give bad drivers an excuse not to care when they take one of you out, and to act in ways that make it more probable. Sadly, it is as likely to be a polite cyclist as one like you.

  10. Pro-reason said,

    February 11, 2009 at 12:36 pm

    NorthernBoy, the idea that a swearword weakens a point is such a tired argument. Are you going to use it against Ben, who says “ricockulous” in his mini-blog?

    I’ve stated that I cycle safely, with the only accident I’ve ever had being due to a motorist pulling out of a side road without looking. He had to pay compensation, by the way. Those are the facts, and if you contradict them without evidence, then you are insulting me for no reason, and can expect a response.

  11. NorthernBoy said,

    February 11, 2009 at 1:28 pm

    Your response makes no sense at all. I did not say that swearing weakened your point, so why did you make that up?

    I said that the insults emphasise the points others have made about the attitude of many cyclists (i.e. that you come on the internet and act like arrogant cocks whose shit does not stink). I said nothing about how strong or weak your argument was.

    It is also funny that you believe that you stating something (i.e. that you are a safe cyclist) also “establishes” it. Assertion and proof are really not even similar concepts. Again, you seem to be getting a bit confused here.

    I am afraid that you are conforming to the internet-cyclist stereotype now, so I’ll leave you to your whining. Cheerio.

  12. kerledan said,

    February 11, 2009 at 9:39 pm

    Crikey! A bit of a Daily Mail moment going on here.

    As I said before, let’s look forward to the day when the law is changed in the UK to be like in Germany or the Netherlands, where if you hit a cyclist or pedestrian when you’re in charge of a powered vehicle, the onus is on you to show it was their fault. I certainly don’t support bad cycling, and with this change in the law bad cyclists would be held much more to account as case law would build up laying down when a cyclist was behaving unreasonably (ie going through red lights).

    A simple change in the law would dramatically reduce the deaths and injury to cyclists.

  13. Pro-reason said,

    February 11, 2009 at 10:20 pm

    Howfar was being stupid, and I called him up on it. You attacked this as infantile, doubtless because I used a swearword. Now you’re backpedalling on this.

    You’re now talking nonsense about shit not stinking, when all I did was reject the baseless assertion that I don’t cycle safely.

    I’m the only person on here who knows me, so if I say that I’m a non-smoker, or a safe cyclist, or have green eyes, then that establishes it as a reasonable fact to go on, until such time as you have some particular reason to dispute it.

    The example of rule-breaking that I gave before involved the fact that it doesn’t matter which way you travel along a street designated as one-way if there is ample room for traffic both ways, and there is no one else there anyway. It’s less dangerous than riding down a normal road with cars on!

    Here’s another one: it’s pointless to stop all by yourself at a red light when it’s 2am and you could hear a pin drop.

    You basically have to be a motorist to think that any of these silly rules ought to rigidly apply to cyclists. As our society becomes more rational, and the number of people driving decreases, we will see your sort of opinions die out.

    Cheerio.

  14. Pro-reason said,

    February 11, 2009 at 10:23 pm

    Kerledan, I don’t think that that change in the law would reduce deaths. I doubt that as motorists are mowing down us pedestrians and cyclists they are pondering the criteria the court will use to decide culpability.

  15. kerledan said,

    February 12, 2009 at 5:04 am

    Pro-reason, I think a change in the law would be a major plus. It would hold drivers to account for deaths and injuries to vulnerable people (cyclists and pedestrians).

    An old article in the Daily Mirror whinges about a European Union initiative to implement such a law across Europe and conforms to the usual piss-poor standard of public responsibility of what passes for journalism in large sectors of the British media. This article actually shows just why this law would be excellent (while spitting bile about it). But this law was never introduced into the UK, of course. It would save lives and reduce suffering from injuries.

    www.mirror.co.uk/news/columnists/parsons/2002/08/05/i-just-don-t-lycra-these-cycle-yobs-115875-12091697/

    The facts remain: if you are in control of a powered vehicle you can kill or seriously injure cyclists or pedestrians. If you hit a pedestrian or cyclist, then, you should be held accountable. A defence would be that the cyclist or pedestrian was at fault. But, like at sea where a vessel under steam has to account for running down a sailing boat, so on the roads.

    One thing I see a lot is people driving too fast down a narrow street with parked cars on either side. 20 mph should be the rule in cities, this way if a child steps out from behind a parked car, the driver has a chance of braking in time or if he or she hits the child the child may well survive. When we have a change in the law in the UK, in this scenario, there could be no defence if the driver was driving at 40 or 45 mph (or indeed 30 mph) following a death or injury. And rightly so!

    Go to Berlin and watch the vehicles proceeding sooo decorously and slooowly.

  16. Pro-reason said,

    February 12, 2009 at 5:54 am

    Ah, Tony Parsons. I’d happily forgotten about him, here in Oz. Amazing he hasn’t been committed to some sort of institution yet.

  17. kerledan said,

    February 12, 2009 at 1:51 pm

    Yes, Pro-reason, in this piece Tony Parsons is being provocative rather than really trying to actually discuss reasonably, IMO, I mean, he wants to be ‘edgy’ as the fashionable term has it.

    But it’s not very good really, is it?

    We can however read it as a piece which actually shows the value of the proposal, rather than as an ‘argument’ against. Why is this bloke laying into a perfectly sensible proposal, we wonder?

    I remember young Tone when he and Julie Birchall were writing ‘edgy’ stuff for the New Musical Express.

    Plus ca change….

  18. Delster said,

    February 13, 2009 at 10:31 am

    @ Pro-reason

    To quote you “Here’s another one: it’s pointless to stop all by yourself at a red light when it’s 2am and you could hear a pin drop.”

    I was sat waiting for a light to go green…at 2:30am…when a car went sailing straight through the red light that was showing on their direction….and ploughed straight into a car coming through the light that was currently green.

    I ended up calling the police & ambulance and keeping the guy who’d been hit alive till they got there.

    There is a reason for these rules which is why you should follow them.

    Just because it’s 2am it doesn’t mean it’s safe to go through the red light….it just means it’s a lower risk than in rush hour.

    Quite frankly if somebody is dumb enough to do something like this and get’s killed then it’s just Darwin in action as far as i’m concerned.

    PS…you might want to look up what an assertion is as opposed to a fact

  19. Pro-reason said,

    February 14, 2009 at 3:05 am

    Delster:

    “I was sat waiting for a light to go green…at 2:30am…when a car went sailing straight through the red light that was showing on their direction….and ploughed straight into a car coming through the light that was currently green.”

    There’s no talking to you if you just conveniently ignore the important parts of what I say and focus on a part you feel you can twist.

    The time only served to emphasise just how quiet it was. If there are no vehicles in the vicinity, there is no danger. You can’t do anything about that fact.

    Assertions and facts are not mutually exclusive.

  20. kerledan said,

    February 14, 2009 at 8:28 am

    @Delster, I agree with you, the rules are there for a reason and I think all roads users need to keep to them.

    @Pro-reason, I think you’re obviously a cyclist like me and have an antipathy to some drivers because of their behaviour and the danger they pose. Me too. But I don’t agree with you about not observing red lights in certain circumstances.

    I also don’t actually think that Delster was twisting your words, it seemed to me that you were stating clearly that there are circumstances in which you think it would be ok to go through a red light: I don’t agree. Delster gives a clear example of one reason why it’s a bad idea to do this.

    Delster was a bit ascerbic of course with his or her apposite reference to the Darwin awards (apposite in that it was the anniversary of Darwin’s birth this week). But he has a point, I think.

  21. Pro-reason said,

    February 14, 2009 at 12:20 pm

    The idea that risk increases when you break a rule is simply magical thinking, and you are not going to be able to get me to indulge in it. It rather reminds me of the notion that succussion imparts qualities to homœopathic water that wouldn’t be there otherwise.

    I can just imagine you all, sitting for fifteen minutes at a malfunctioning traffic light, given that there are apparently no circumstances in which you think it would be OK to go through a red light.

    You choose obedience, and I choose sanity.

    Would riding on the pavement be another cardinal sin in your book? The knowledge that I spent 20 hours this week doing so perfectly safely and also *legally* will surely send your head spinning with cognitive dissonance. I’ll make a mental note to do it for a few minutes illegally to. By your standards, those minutes will be more foolhardy and Darwin-tempting than the 20 hours.

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