Rob,
You have overlooked the fact that I did not overlook the work of Jeremy Broughton. In my first Significance article (June 2007) I did comment on the work of Broughton (with Stark). Please see Figure 6. I went on to note “no studies have been done so far [by Broughton or anyone else] to explain why, after the seat belt law came into effect in Britain, seat belts were so extraordinarily selective in saving the lives only of those who were over the alcohol limit and driving between 10 at night and 4 in the morning.“ Please look again at Figure 6 and the graphs in my earlier post; can you explain why seat belts were so extraordinarily selective in saving, almost exclusively, the lives of drivers who had alcohol in their blood, and driving between 10 at night and 4 in the morning? JA

PS “What I term ‘inflation’.” Do you still think that the seat belt law has saved 2400 lives per year? Or 372? Or 164?

PPS In your Significance article you say “They [seat belts] prevent many more deaths and injuries than they may cause.” Is it your view that it is OK to save the lives of motorists at the expense of those of pedestrians and cyclists so long as the former are more numerous than the latter?

On a point of detail, the “cycle helmet law” you refer to is actually for motorcycle helmets. There are no all-ages cycle helmet laws in the US. 22 states have child cyclist helmet laws, but few, if any, are enforced in any significant degree. For instance, in California there is such a law, but this does not prevent Miley Cyrus and friends riding their cruiser bikes around without helmets. Fortunately the LAPD recognise a waste of time when they see it.

I should have thought the greatest mileage in criticising seatbelt laws (as a mistake not to be repeated) would be to focus on deaths to cyclists and pedestrians. The result above shows 38 extra cyclist deaths in 1983, a year in which there were 323 reported cyclist deaths. That would mean that about 1 in 8 cyclist deaths that year were due to the seat belt law. That is quite an awesome conclusion, in terms of the injustice and cynicism of a state that imposed such extra risk on those pursuing a harmless, healthy activity – especially now that there is so much push today to get mnore people cycling.

There is also a lesson to those opposing cycle helmet laws. There is nothing that law campaigners will not stoop to to get their way. Take a look at my response to a paper published in Pediatrics last year:

http://pediatrics.aappublications.org/cgi/eletters/122/3/605

Draw your own conclusions as to the honesty of the authors of that paper. Despite this, the paper got quite wide publicity. So spreads myth in an open society.

A big difference between seatbelt laws and cycle helmets is that credible evidence exists from car wreck analysis that seatbelts confer life-saving benefit, at least at speeds below about 50mph. Whereas, no such credible evidence has ever been forthcoming about cycle helmets. The most detailed studies show no reduction in serious injury either in collisions or in falls. The data were reported to show otherwise, because the authors were well aware that acceptable conclusions had to be provided. They were, however, honest enough to admit in the text, by the by, that their conclusions rest on quirks of the data, rather than any helmet effect.

For me, the real giveaway is that no study has ever appeared showing effectiveness based on damage to helmets in real crashes. This is becaise researchers who have gathered helmets have failed to find any that showed crushing of the liner. Rather, the helmets just broke apart.

Malcolm
Many thanks for the correction about the Mississippi helmet law. Whether the law refers to bicycle helmets or motorcycle helmets the point still stands; see my article “Public Safety Legislation and the Risk Compensation Hypothesis: The example of Motorcycle Helmet Legislation”
Thanks also for calling my attention to your excellent letter in Pediatrics. It is a devastating critique of an article calling for compulsion. Characteristically there has been no reply. Campaigners just keep campaigning.
Another superb source of information on the subject – the most comprehensive I know – is Guy Chapman’s Cycle Helmet Portal.
JA

You say:
” In your Significance article you are clear that the law has saved the lives of people in cars at the expense of vulnerable road users: “The picture shows a clear reduction in death and injury to car occupants, APPRECIABLY OFFSET BY EXTRA DEATHS AMONG PEDESTRAINS AND CYCLISTS.”(MY EMPHASIS – Rob Giffords words).

John , you then go on to give a (blackly) amusing analogy. One can put this in a less dramatic way: doctors – and doctors are among the main proponents of such types of intervention – are required by their ethical code (the Hippocratic Oath) to “First, do no harm”. You appear to admit that this is precisely what they have not done – that they have killed people in the most vulnerable, and least dangerous to others, road user groups in the name of “road safety”.

For this reason those of us who are supporting the most benign and healthy forms of transport are unlikely to trust PACTS, RoSPA and others supposedly concerned with safety on the road ,of which bicycle crash helmets are just one issue.

If Gifford values his reputation among those concerned with the safety of all road user groups and the genuinely scientific community, I suggest he reconsiders as John suggests.

Firstly, the obvious truth of adaptive behaviour or risk compensation is central to contemporary discussions of some very positive episodes: the good experience of safety with “shared streets” and the decline in casualty rates among London cyclists as just one example of “safety in numbers” with numbers of cyclists approaching “critical mass”.

Secondly, the obvious truth of adaptive behaviour or risk compensation indicates that the relentless idiot-proofing of the driver environment – whether of the vehicle or highway – has produced idiots in such a way that the “road safety” lobby is hardly well qualified to pontificate on matters of cyclist or pedestrian safety – of which cycle helmets is just one. No doubt this is a main reason for the denial of such effects from the “road safety” establishment.

Thirdly, the obvious truth of adaptive behaviour or risk compensation indicates that supposed progress in declining RTA fatalities and other casualties may have resulted from adaptive behaviour by the most benign and vulnerable road users ,as opposed to “road safety” interventions, including migration from the road environment entirely. Again, this might explain some denial from practitioners of “road safety”.

Finally, the obvious truth of adaptive behaviour or risk compensation indicates that some changes in fatalities are due to changes described by the Smeed and Adams curves, and are independent of interventions claimed by “road safety” professionals.

All of this suggests that denial on their part is understandable, but not acceptable to those of us concerned with the safety of all road users and the truth.