The hierarchy of safety

The hierarchy of safety, as understood by risk management professionals, is more or less stated as:

  1. Reduce risk at source
  2. Reduce exposure to risk
  3. Personal protective equipment

This is pretty uncontroversial.  The BMA in its position paper on cycling safety offers a number of suggestions, with helmets being the most prominent by far.

Nothing wrong with that, you may say.  But consider the following example form my early career.

A university project team was working with an abrasive wheel manufacturer on process improvement. The MD wanted us to design an automated system for testing the balance of “green” wheels (i.e. before curing in the ovens; the material from a green wheel can be recycled into the mix, once cured it cannot).  The intention was to reduce balance rejects post-curing.  All that sounds perfectly reasonable.

As part of the investigation of the problem my colleague Neil had analysed the correlation of balance issues with a number of other factors.  These were not randomly chosen, they were all taken from interviews with the chief engineer and production director.  These two guys had been in the business a long time and were well aware of the causes of the problem, and they were absolutely right.  Balance problems were greatest when the mix had been left to normalise for a short time, and least when the mix had normalised for the recommended period.  Problems varied with the temperature and humidity in the mixing bay (the mix, of phenolic resins and abrasive grits, was hygroscopic and very sensitive to atmospheric humidity).  We investigated other production plants and made two recommendations:

  • That the mixing bay be enclosed and air-conditioned
  • That the mixing bay shift times be changed to start two hours before the rest of the factory

Neil’s analysis indicated that this would reduce the balance variation to the point where the existing batch testing regime would be sufficient, and also reduce downtime to adjustments.

What was the company’s reaction?

We were told to go ahead with the automated balance system and then think about the mixing bay project later.  So: pursue the more expensive option, then pursue the lower-cost option which would make the expensive option unnecessary.

And I see parallels in the BMA position paper, and indeed in virtually every helmet promotion campaign.  Helmet promoters are beginning to reinvent themselves as “cycle safety advocates” and are having to acknowledge the role of training and driver education, among other factors, in cycle safety.  But still they put helmets first.

The problem with this approach is exactly the same as the problem at the abrasive wheel company.  A solution has been decided on, and it does not address the root cause.  Addressing the root cause would prevent collisions rather than trying to mitigate their effects, and would make what is already a reasonably safe activity even safer.  Thus reducing the supposed need for the solution.  And by the way probably helping with the much larger problem of the number of pedestrians killed and injured on the roads.

This is why I prefer the CTC approach to that of people like BeHIT.  CTC looks to reduce risk at source; we can then see if it is still necessary to reduce exposure to risk (i.e. by promoting cycleways and other engineering measures), and once the effect of these is clear, well, if the problem is still apparent (if indeed it is apparent in the first place, which I would dispute), then we can consider protective equipment.

Unfortunately the cycling community has wasted most of the last twenty years on helmets, and is coming very late to the realisation that the evidence for their effectiveness against the sources of risk is questionable.

Further reading

For more on the philosophy of risk and risk management I recommend the excellent John Adams and his blog “risk in a hypermobile world”.