Posts by linger
Last ←Newer Page 1 2 3 4 5 Older→ First
-
Oh -- and one reason why NZ's experience is used as the reference point for assessing the effects of helmet laws is that we introduced our helmet law ... and, rather stupidly, did nothing else to increase the safety of cyclists. Basically, in one of the earliest implementations of the "user-pays" philosophy, we chose the one solution that put all compliance costs on individual cyclists, and ignored anything that would involve increased public expenditure.
-
Once again, it's not about whether you wear your helmet or not (though you should). The argument is not (and the model does not imply) that one cyclist choosing to wear a helmet somehow magically increases the danger to other cyclists.
-
Neither Cochrane metaanalysis cited really adds anything.
The first is not really relevant to the wider population risk analysis. It concludes that helmets improve outcomes from an accident, once that accident occurs: but that has never been subject to question.
The wider questions of whether helmet laws end up increasing the accident rate per cyclist , and whether cycling leads to improved health, are simply not addressed.
The relevant conclusion of the second study is simply that (in 2008) there hadn't been much study into whether helmet laws affected cycling rates. That is not a statement negating the possibility of any such relationship.
Expanding on my earlier "path-dependence" comment: there are a number of features of the way the NZ helmet law was introduced that amplified its chilling effect on cycling uptake, and it is for these reasons that I think repealing the law would be insufficient by itself to recover the popularity of cycling to pre-law levels.
(i) an effective, prolonged, emotive campaign -- delivered via a medium which was at the time focussed on a very small number of state-owned outlets -- first arguing for the law change, and then informing the public of the new law, emphasising the dangers of helmetless cycling. It was a campaign built on fear. Such campaigns are easy to conduct, but just about impossible to reverse by the same mechanism, especially since there is no longer a single platform on which the audience is as concentrated.(ii) a fine level imposed equivalent to the cost of a bicycle (though in practice, if I remember correctly, there was a grace period during which helmetless cyclists were warned rather than fined). Such a cost is prohibitive for many cyclists, and particularly for children. An interim measure worth looking at to evaluate the effect of this feature alone would be to keep the law in place, but to remove the fine, with offenders only to be warned.
Whatever happens to the helmet law, other measures would also have to be pursued to increase the safety of the cycling environment (increasing participation, improving infrastructure, and educating motorists).
-
Hard News: Fear of Cycling, in reply to Moz,
Here’s the thing. I’m convinced that enacting the helmet law had immense negative effects on culture and attitudes around cycling in NZ, with long-term impact on infrastructure, and that after the event it can be seen as an appallingly bad decision; but I’m not convinced that repealing the law now would undo the damage anywhere near as quickly. There’s causation – but there’s also path-dependence.
-
Hard News: Fear of Cycling, in reply to Kevin McCready,
Except that those same children will have been brought up to consider cars more “normal” than bicycles, and to consider bicycle helmets a “normal” indicator of a perceived high risk associated with cycling. The problem is not helmet aversion as much as cycling aversion. (See title of this thread.)
-
Hard News: Fear of Cycling, in reply to Carol Stewart,
The nature of the cycling infrastructure also is forced to change as the proportion of cyclists increases: roads cannot continue to be planned as car-only zones if more than a third of the traffic is going to be by bicycle. Admittedly Wellington does offer more challenges to a cyclist (and in general, to infrastructure development). David’s original comparison was between Christchurch and Copenhagen, which are in the main equivalently flat (as he pointed out, Chch actually has a climate somewhat more conducive to cycling than Copenhagen’s).
In Copenhagen, of course, there was deliberate infrastructure planning to encourage cycling. In NZ, we’re playing catch-up, with the infrastructure in most areas lagging well behind what is needed now , let alone planning to encourage future expansion of cycling. -
Hard News: Fear of Cycling, in reply to BenWilson,
Looking back at David’s original calculations, the important comparison is of overall health and wellbeing between a cycling population and a non-cycling population. The main components there are:
* conditional probability of severe injury from an accident (significantly reduced for some classes of less severe event by helmet use – though not much in a collision with a high-speed vehicle, as that’s not what the helmet is designed to protect against);
* probability of getting into an adverse event resulting in injury (which decreases on increasing the number of cyclists and decreasing the number of motor vehicles, through multiple mechanisms as already listed, including e.g. more positive attitudes of motorists to cyclists, resulting in more considerate driving around them; improved infrastructure for cycling; and lower traffic density);
* population-level health benefits of exercise associated with cycling vs. transport not involving exercise (= far more than enough to outweigh the injury costs of cycling);
* highly negative effect of mandatory helmet laws on taking up cycling (in NZ the absolute number of cyclists halved around the time the law was introduced).
Thus the helmet law (but not helmet-wearing itself!) can be shown to have a highly negative effect on overall health and wellbeing of the population, even if, for an individual cyclist, wearing a helmet offers some benefit.But, yeah, humans are generally fairly useless at balancing up probability of an event with the severity of the outcome: we generally focus on the latter type of (anecdote-driven) story at the expense of the former (statistics-driven) evidence. In this regard the parallel with the other currently ongoing discussion (of drug regulation) is fairly striking.
-
Hard News: What the wastewater tells us…, in reply to Joe Wylie,
if it’s good enough for Bill English
Knew he had to be on something to be coming out with that … :-)
-
Creatinine could be a more general control for volume of kidney output, as opposed to volume of water flow through the sewage system, which will also depend on other factors such as rainfall; hence it would allow normalisation of other readings to refer back to numbers of people.
-
Hard News: Fear of Cycling, in reply to Stephen R,
Basically, what you’ve most got to guard against is:
a dick in a box on wheels.
But it’s not easy to predict the contents from the shape of the box,
as shown by the fact that different experiences lead to different predictors.