Thanks for this Philip. I have had a chance to read Charles Lamb’s paper and while I don’t want to diminish the importance of his conclusion that improving conspicuity could reduce some multi-vehicle motorcycle accidents (MVMA), I don’t find his report or remaining conclusions particularly helpful when his analysis excludes over a third of all motorcycle accidents, namely solo crashes. He seems to be implying, as a result of his selective analysis, that the current policy formulation in the area of ACC m/c levies or m/c road safety generally (the former being a subset of the latter) is flawed, which I think applies more to his paper. Consequently, I read his statement (p2) that differences in interpretation of accident statistics offer the potential for distorting and misrepresenting the accident situation and that the “conclusions that should be drawn from a dispassionate analysis of the data” forms the basis of his research, with more than a hint of irony. No policy analysis, the AA’s included, would exclude such a significant proportion of m/c accidents and the causes thereof when trying to draw conclusions, social cost estimates, and recommendations about them. If he restricted his comments to solely MVMA then his conclusions about visibility are valid but he cannot draw conclusions about all m/c accidents from his selective analysis.
I also find the comments in his opening slides somewhat inflammatory and its not clear what the purpose of such a piece of research is, certainly not what it purports to be and I don’t think it makes a positive contribution to the debate.
I would be concerned if motorcyclists read this report and assumed that conspicuity is the silver bullet. By his own analysis it is only a factor in 38.6% of MVMA accidents, which equals less than 25% when you include solo m/c accidents in which visibility is probably not a factor (except lack of on the riders part). He also notes in his PowerPoint that 40% of m/c accidents are caused by other road users – which means 60% are more likely to be the fault of the rider? How will conspicuity address this majority? In terms of setting policy we should also consider the causes of the other 75% of m/c accidents where conspicuity isn’t a factor. He seems to try to diminish the value of other safety initiatives, or enforcement of crash causes like speed and alcohol, yet our analysis of CAS (serious and fatal m/c crashes only), which you have, shows poor handling is the most common cause (18%), followed by speed (16%) and alcohol (9%), combined these are much greater than visibility which is the opposite of what he concludes.
I note he refers to the “87% of motorcyclists at fault” quote in the paper, and attributes this to the AA in the PowerPoint, although he does not acknowledge the source or try to verify it. I don’t know where he got it from, probably copied email correspondence, but where we have used that figure it has been with the proviso that it was an analysis of the very same CAS data Mr Lamb uses in his report, but only relating to serious and fatal m/c crashes. This was in response to the ACC debate last year, the point being that not all m/c crashes lead to ACC claims. Yes, it was a selective use of data just as he has done, but more relevant in this case to try to understand ACC’s policy setting. I hope he doesn’t think that ACC use non-injury or minor injury m/c crashes to set levies as these are unlikely to impose costs on ACC, yet he has included such crashes while excluding a third of all m/c accidents, serious or not. An example is his revelation that there are more accidents involving 21 year olds on 250cc ‘bikes. Could it be that several accidents involving young, fit males on low incomes impose less costs on ACC than a single accident involving a well-paid older male on a big bike? Could that explain ACC’s differential levy? You can’t conclude that from crash data alone.
I also have concerns with some of the data he has published. He states that the number of m/c injury crashes per 10,000 ‘bikes was 121 in 2008, and attributes this to MoT (and CAS), yet the MoT crash report puts this at 142 (the same under-reporting applies to previous years’ data). He offers no explanation as to why this is different and I am concerned his data, especially being attributed to the MoT, will be taken as accurate when the graphs he derives from these underestimate what is a worsening trend, the very problem road safety advocates are trying to address (also, if he compared the same data with the trend for passenger vehicles, his graphs would look a lot worse). I am very surprised Mr Lamb has published this data and attributed it to MoT without querying the variance and stating why his figures underestimate previously published authoritative and peer-reviewed data by a significant margin. This brings into question the validity of the remaining CAS analysis in his report.
I could also add that I find his choice to restrict individual analysis of CAS reports to Auckland and Christchurch odd. These have huge urban networks (and safer motorways) and so would include a large number of lower speed accidents – again the sort of accidents that don’t result in big ACC costs (if that was the original driver for this research). Our analysis of CAS (all road crashes) shows a majority occur on the open road which, at higher speeds, are obviously more serious, so only reviewing the data from two major urban areas distorts the true picture of serious crashes in NZ. A better sample would have been the Waikato or Manawatu for example which gives a better urban/rural split.
Neither Mike nor I know Mr Lamb but we will arrange to meet with him to understand some of the parameters he has chosen for this research and also the reasons for differences in data values from the same source, as well as having a general discussion about m/c safety and local and international research which he may be able to assist us with.
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Originally Posted by oldrider
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