Saving the Unicorn

23 July 2014

Recently, Jersey voted overwhelmingly to make cycling helmets compulsory for under 14s. It turns out this was based on a report from the Transport Research Laboratory. Let’s take a look at it, then.


I’m going to ignore the material pertaining to the efficacy of helmets in individual incidents. Partly because it’s a can of worms that warrants an extensive article of its own; partly because, as we shall see, it turns out to not really be very important.

I should also add that I’ve not read all of the cited references. There are 68 of them and I simply don’t have the time. There are a couple that stand out when reading the report, which I shall endeavour to read at a later date, but what I’ve written here is based on the TRL report only. I don’t consider this unfair: the report should stand on its own merit, and will doubtless have been treated accordingly when the legislation was passed.

Let’s jump into the report at section 4.

Helmet wearing rates

Section 4.1 (p27) discusses helmet wearing rates in states and countries where helmet use falls into one of three categories: optional, compulsory, and enforced.

It notes that in the Australian provinces of Queensland and Victoria, compulsion caused helmet wearing rates to jump from 31 to 75% and from 16 to 52% respectively, with Queensland’s rate continuing to rise to match that of Victoria.

It notes that in Alberta, Canada (which has compulsion for under 18s), rates for under 13s rose from 75 to 92%, and from 30 to 63% for 13-17 year olds; also, that Nova Scotia (with universal compulsion) has helmet wearing rates of 77% in youths and 71% in adults, Ontario (under 18 compulsion) has corresponding figures of 47% and 39%, and Saskatchewan (no compulsion) has figures of 33% and 25%.

It is worth pointing out that in the context of helmet wearing rates, the TRL report makes no comment on the cycling population figures before and after legislation. Take any two mutually exclusive sets, and if you reduce the population of one, the rate of membership of the other increases. In other words, a rise in the helmet wearing rate among cyclists can be achieved by more cyclists wearing helmets, or by fewer non-helmet wearing cyclists cycling. In reality there will be a combination of both, but TRL do not discuss this here.

If, however, we optimistically assume that there is zero discouragement from cycling, we note that of the non-helmet wearing population, around half obey the new law.

The pessimistic assumption, of course, would be that none obey the new law, and half cease cycling; the reality would be somewhere in between. I do not buy TRL’s rather odd counter-argument to the population drop effect, that—

It is also possible to argue that mandating helmets could be perceived by the public as an act by authorities to improve cycling safety in general, thus overcoming what is known to be a major barrier towards cycling.

—because anyone who feels cycling is made safe by wearing a helmet has the option to do so, and anyone who feels that the cycling environment poses a risk against which they consider a helmet insufficient protection is only going to have that feeling reinforced if authorities acknowledge that problem by mandating helmets instead of addressing it.

(Amusingly/tragically, TRL follow their curious hypothesis with, “Evidence is more important than intuitive-sounding counter-arguments, whichever way they are aligned with regard to the debate.” – but I digress.)

Now, bear in mind those rates and let’s skip to the data from Jersey.

Take a look at section 6.1 (p36).

The current helmet wearing rate for under 17s in Jersey, with no legislation in place, is 84%.

Compare that to the rates above and it’s astonishing. It’s higher than most places with compulsion, and by no small margin. And, as noted later in the report, it’s rising.

This figure gives credence to one of TRL’s conclusions, which is that compulsion is unlikely to have a major effect on cycling participation on the island.

However, in the context of its other conclusion – that legislation can be expected to provide benefit – it raises a key question: Since helmet wearing rates are already well above those which might normally be expected under compulsion, what will compulsion achieve? The absolute best it can achieve is to encourage 16% of children to wear helmets, but figures from elsewhere suggest that at most this will be 8%, and that’s before we consider any reduction of the cycling population.

But the data from Jersey gets even more interesting.

The unicorn

The TRL guidance considered casualty data from Jersey. Curiously, there is only one year’s worth of data given in the report, for 2013, but it’s notable that cyclist casualties on Jersey were exceptionally high in 2013. Most years have seen markedly fewer casualties.

Have a look through figure 6-3 on page 39, which lists all cycling casualties by age and gender.

Now, remember that Jersey’s law applies to under 14s.

That table lists just two casualties for under 14s: two boys aged 11 and 13, both slightly injured.

Head and brain injuries are not slight injuries. And slight injuries are, other than being markers for incidents, not really of interest in the context of public health.

So – and here is where we realise can ignore the discussion about efficacy – where is the problem that helmet compulsion is supposed to address? The report contains no evidence that it exists. None.

Remember, the legislation will only have an effect where:

  • the individual is under 14, and
  • is in the 16% not already using a helmet, and
  • is in the 50-100% of that 16% who will start using a helmet rather than not cycle, and
  • is in the 50% at most of that 50-100% of that 16% who – given the pre- and post-compulsion data cited in the report – will actually obey the law, and
  • is involved in an incident in which, without a helmet, they would sustain a head injury, and
  • the incident is of a nature where the helmet makes a substantive difference to the outcome

All of these criteria must be fulfilled by at least one individual if there is to be any gross benefit at all (ie disregarding any disbenefit). The last point heads into a very speculative area, where section 3 of the report (regarding efficacy) becomes relevant, but the available data – the data cited in the report – shows that before we even get there, the set of potential beneficiaries is zero.

Of course, despite the lack of data, over the long term the chances are it’s not zero – but it’s without doubt very, very small; and once the rest of the points are accounted for, the probabilities of any benefit dwindle to negligibility. If there occurs an incident in which a helmet makes a substantive difference, there is between a 4 and 8% chance that the legislation will have caused a helmet to be worn where it otherwise would not.

Chance of any positive effect: a low probability, times a low and unknowable probability, times roughly 6%. And then multiply it by the health benefit the helmet actually gives; at which point we’re into the can of worms that is section 3 of the report.

And remember, this is purely gross benefit we’re talking about. Not net benefit.

A solution to what?

When forming their guidance for this legislation, the TRL considered a set of data which contained two people to whom it would apply, and for neither of whom compliance with that legislation would have made any difference.

Of course, any inference that the legislation is totally futile is a little undermined by there only being a single year’s data on offer; but then, the exact same can be said of TRL’s opposite inference, that legislation is worthwhile.

Significant time and money has presumably been invested in the report. It’s understandable that it covers matters such as helmet efficacy, but it’s hard to see past the rather more prominent fact that based on the available data the legislation is incredibly unlikely to achieve any positive health benefit.

Helmet wearing rates are already exceptionally high and rising; casualty rates of the target population are already exceptionally low. Jersey is achieving better voluntary helmet use than legislation normally achieves.

This is the “if it saves one life” line of thought distilled to absurdity: the data show no lives to be saved, nor even any injuries to prevent. All of the statistics point to there being no effect even if helmet use runs to 100%, and even if no-one is discouraged from cycling.

TRL’s advice is that “legislation requiring the wearing of cycle helmets in Jersey can be expected to have a beneficial effect on the injury rates of those impacted by the legislation“.

Yet the data in the document do not bear this out. Not in the slightest.

So… why was this legislation introduced?

Conspiracy theorists, it’s over to you.


So, who is dying from head injuries on Jersey?


  1. Cycling Anomaly (@lastwheel) 23 July 2014 11:19pm #

    I prefer intelligence analyst and I’ll get back to you perhaps. Synopsis is that Belfour Beatty which should be a name familiar with anyone with a passing interest in (un)civil engineering, is a feeder club for TRL.

  2. wheelsonthebike 24 July 2014 8:14am #

    A trial run for helmet compulsion laws in the UK. “It worked in Jersey! There have been no deaths or serious injuries since!”

  3. Andy 24 July 2014 9:23am #

    I’m afraid there are a couple of (cycling related) reports produced by TRL where it feels like the conclusion came before the analysis. Another is their study on cycling infrastructure (PPR580?).

  4. Antony 24 July 2014 11:27am #

    It’s an easy win, which will be used to try and justify legislation elsewhere. Andrew Green, the Deputy responsible for pushing this legislation, is chair of trustees of Headway UK and has previously tried unsuccessfully to get helmets made compulsory for all ages (his official role is actually minister for housing, but hey).

    This report and TRL’s PR around it all has a distinctly Friday afternoon feel, from the erroneous reference to Jersey being part of the UK, to Richard Cuerden’s misdescription of anti-compulsion campaigners as “anti-helmet advocates”.

    As an aside, does anyone know if the Road Safe Jersey website counts solo accidents as well as RTCs?

    • Bez 24 July 2014 11:30am #

      What I’ve read leads me to understand that yes, those figures include single-party incidents; though I can’t put my finger on an explicit statement to that effect.

      • Antony 24 July 2014 12:26pm #

        TRL seem to think that either the figures don’t include single-figure casualties, or they dramatically under-report them. From their PR spiel:

        “As part of the study TRL found that one of the challenges is the lack of information regarding the size and nature of the cyclist casualty problem. This is because the vast majority of single vehicle cycle accidents that result in hospitalisation are not reported to the police and there is only limited hospital data available on the injuries sustained. Nonetheless, they represent a significant number of hospital admissions and associated costs to the NHS, not to mention the personal tragedies for those affected. Therefore, we recommend more work in this area to better quantify and describe the characteristics of injuries sustained by cyclists, with and without helmets.”

        As an aside, isn’t it time that any scientific study purporting to be independent disclosed its source of funding, its brief, and the contents of any informal chats with the client in the run-up to its production? Otherwise it might just as well go in the pile with that study funded by Mars which found that chocolate was good for your teeth.

        • Bez 24 July 2014 12:35pm #

          Yes, sorry, I meant reported ones, but TRL are most likely right in that a significant number go unrecorded in RTI data. I would, however, suspect that the majority of unrecorded ones are minor injuries, but that’s making assumptions about the data gathering process. So – yes, there will be some unknown set of data.

          The report states that 40 cyclists presented at Jersey’s hospital with some form of head injury, of whom four had been on the road at the time of the incident. I’m not sufficiently familiar with Jersey to know what the “off-road” environment looks like (eg, would this include private roads, unmetalled roads, etc?)

      • Antony 24 July 2014 1:33pm #

        It doesn’t seem to be a mountain biking mecca, but there’s a bit of that going on. They had an urban DH race there last month – that’ll probably skew next year’s stats a bit.

        Apparently 50 miles of roads are designated “green lanes” (with a 15 mph limit), so maybe that accounts for the large number of “off road” incidents.

  5. Ian 24 July 2014 11:29am #

    Possibly because Andrew Green, one of the prime movers, has a son who was injured after being knocked off hisbike. Mr Green is understandably keen to do “something”, and this is the cheapest something, and the least likely to annoy his carist voters.

  6. Helen Booth 24 July 2014 11:39am #

    I’m afraid I am deeply suspicious of this report and it being used to force through helmet legislation in Jersey. I believe TRL most certainly does have an agenda, and that agenda is to eventually force every cyclist in the UK to wear helmets. The ‘cycle safety’ box can then be ticked, without having to spend a penny on infra or challenge our carsick culture, where the driver is always king. We need to keep a close eye on MP Annette Brook’s research bill on helmets for under-14s. It has a second reading on 12 September. My fear is that this is just the beginning…

    • Nico (@NicoVel0) 24 July 2014 11:55am #

      They’re in for a fight. LCC, CTC, British Cycling, AA, RAC (I think) are all against compulsion. Plus many will never comply.

  7. paulmilnepoetry 24 July 2014 12:30pm #

    It’s a box-ticking exercise. They thought it would be a shoe-in for Jersey precisely because it will have no affect one way or the other. Yet they can point to themselves as making a move for safety with no fear that any difference on cycling rates will be affected.

    If anti-helmet-freedom campaigners (see what I did there? Spin can work both ways …) can point to a “successful’ roll out somewhere relatively close to the UK, they may feel they have a better chance of persuading a gullible parliament into doing something that makes it look as if they are doing something, when in fact they are doing nothing.

  8. Sav Szymura (@savszymura) 24 July 2014 5:25pm #

    How about the shops and companies who make and sell helmets? Must be quite a business.

  9. Dermot 24 July 2014 9:55pm #

    I don’t think there’s a conspiracy here really. Headway in every jurisdiction in which it operates (UK, Republic of Ireland, Channel Islands) campaigns relentlessly for helmet laws, searching out parliamentarians to sponsor bills. When one attempt is shot down, they start another one, and then another one, and so on. Where all-ages laws are not a possibility in the short term, they put all their energies into under-14 laws, I assume as a sort of bridgehead to all-age laws. They’re quite open about what they’re doing, though their use of data in support of their campaigns is highly selective, to the point of making them appear either incompetent or dishonest.
    Recently, this proposal surfaced in the Republic of Ireland:
    That one seems to have gone nowhere, but it is similar to the successful campaign in Jersey. A bill in Northern Ireland, which went from an under-14 bill to an all-ages bill, failed in the last few years as well.
    What intrigues me is that if I knew nothing about Headway apart from what I see in the media I would assume it was purely a pressure group for bicycle helmet laws. I saw a comment on a CTC forum thread that suggested that head-injured cyclists make up a small percentage of their clients, so I’d like to know why they devote so many resources to this. I don’t doubt they genuinely think helmets are effective (though they are stone deaf to any contradictory information), but even if they were right, is this the best use of their time and money?

  10. Kevin Fallon 25 July 2014 9:33am #

    Another excellent article but please would you not keep misusing the phrase “begs the question”. It does not mean “raises the question”. Thanks. 🙂

    • Bez 25 July 2014 10:49am #

      OK, I might try to stop abusing it. I’ll have to let my inner pedant duke it out with my inner lover of linguistic evolution 🙂

  11. Helen Booth 25 July 2014 10:33am #

    Agree Dermot Headway are relentless in their campaigning to force through cycle helmet legislation. Yet at the same time, strangely not interested in campaigning for helmets for motorists and pedestrians, who are often MORE at risk of head injuries than cyclists. Personally I can’t get my head around it. Seems completely wrongheaded to me!

  12. michael 25 July 2014 3:15pm #

    “It is also possible to argue that mandating helmets could be perceived by the public as an act by authorities to improve cycling safety in general, thus overcoming what is known to be a major barrier towards cycling.”

    It’s also possible the moon is made of cheese and the Apollo landings and every reported observation of that body was faked.

    Really, that quoted paragraph is just beyond words in terms of desperate attempts at justifying a pre-decided conclusion.

    All the actual data (e.g. from Australia) suggests the (inutitively obvious) opposite – that compulsory helmet laws lead to a substantial drop in cycling rates.

  13. Roger Geffen, Campaigns & Policy Director, CTC 25 July 2014 9:40pm #

    Excellent posting Bez. Just one tiny quibble:
    “Significant time and money has been invested in the report.”

    Actually, it was only commissioned after CTC co-ordinated a joint letter, also signed by British Cycling and Sustrans, urging them to delay a vote on the proposed legislation which was originally due to have taken place on April 28th.

    We asked for an opportunity for Chris Boardman to be able to give evidence against helmet-compulsion, together with experts on health, assessment of risk etc. Instead they commissioned this rapid desk-based review, inviting us to submit evidence only. They then published the resulting report ONE DAY before the delayed vote on the law, giving us no time whatsoever to comment on it.

    See more here:

    • Roger Geffen 26 July 2014 2:54pm #

      P.S. Apologies, a word went missing. My penultimate sentence should have said “… inviting us to submit **written** evidence only.”

  14. Downfader 25 July 2014 11:56pm #

    Just a note on Headway. In 2010 I emailed their head office and asked if they received funding from any motoring companies or organisations. What I got back, iirc, was a jumble of comments about the “good work” they do for victims of head and brain injury. That was not the question I asked.

    To charities that support compulsion: Just be honest.

    If they and others with a similar standpoint DO have these links and these funds to access can we assume a conflict of interest or a guilty conscience?

  15. Dave H (@BCCletts) 26 July 2014 12:28am #

    Perhaps receiving support from suppliers of helmets might be seen as a conflict of interest, receiving support from groups likely to gain from diverting the focus from other safety issues would be a harder one.

  16. Dave H (@BCCletts) 26 July 2014 12:47am #

    For those tracking the distressing state of affairs in Australia, you might want to mine a report by Austroads – you have to register for the free download.

    Daily cycle used has fallen between 2011 and 2013 reports, in some states by a really appalling 8+ percentage points. Yet more bikes are being sold and bike sales exceed car sales – so some could claim cycling is on the increase. However the survey does not as far as my early scans have found look at the cyclist demographic but I suspect we are seeing an N+1 market and an increasing bias towards MAMIL’s with high end machines that are used very infrequently and kept in pristine condition.

    It would be interesting to look at this in more detail as I’d guess the image of an Australian claiming to be a cycle user is worlds apart from a Dutch or Danish one.

    Some good details coming back from the Glasgow MACH bike hire scheme – with just 300 bikes out there were 600 hires yesterday – barely a week after the scheme was launched, and I’ve seen normally dressed folk whizzing home on the bikes as late as 23.45.

    Clearly the tariffs and operating regime seem to be about right – its possibly cheaper to take a bike out for an extended hire than get a couple of taxis for a night out.

  17. Andy 27 July 2014 5:17pm #

    “Evaluation of the 3 m drops demonstrated that helmets only offer a finite amount of protection. At impact speeds of this velocity the energy management capability of the helmet is saturated and the EPS liner bottomed out. If the energy absorbing potential of the helmet is greatly exceeded, it may no longer offer a significant advantage over the bare head condition. However, the 7.7 m/s impact speed in this case is unlikely to be representative of most real-world bicycle impacts”.
    PPR 697, Para. 3.1.3

    Knowing this it’s a good job that a 17mph (7.7m/s) impact speed is, quote “unlikely to be representative of most real-world impacts”, including, one hopes, those impacts taking part on Jersey’s “‘green lanes’ with a designated speed limit of 15 mph…roads [that] are believed to be popular with cyclists”.

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