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[Vic] Characteristics of fatal motorcycle crashes

Discussion in 'Research, Studies, and Data' at netrider.net.au started by hornet, Jan 12, 2010.

  1. Despite some modern attempts to downplay the significance of the 1981 Hurt Report, Dr Hurt's findings are telling and significant influencing factors, with the exception of compulsory helmet useage, in accidents have not changed. http://en.wikipedia.org/wiki/Hurt_Report



    Reading of his 55 points of findings is most instructiive; note points 1, 7, 23 & 27.
     
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  2. From the Hurt report, for me 14 (conspicuity), 25 (inexperience on current bike), 28 (braking error), 40 (ATGATT) hit home as well as the points you mention hornet.

    As the report is American it's interesting that not wearing helmets and the motorcycle riders involved in accidents are essentially without training; 92% were self-taught or learned from family or friends. At least here helmets are mandatory and we enforce training, limited as it is.
     
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  3. Interesting stuff, and bears out what we pretty much already know. The scary part of it for me is the summary paragraph.

    "The current study highlighted the need to improve and standardise the data that is collected regarding traffic crashes in Victoria. In conducting retrospective crash investigations, however, it is difficult to collect evidence on driver behaviour (particularly human error and the pre-conditions) prior to the crash. Driver behaviour and human error are likely to be related to speed-involvement in a crash. Prospective studies should be conducted to enable the study of these important factors. Two potential study methodologies are recommended. The first is a case-control study of motorcycle crashes involving in-depth examination of the crash scene to estimate crash speed and interviews with the rider to reveal the circumstances surrounding the appropriateness of the speed at the time of the crash, to compare with a random sample of non-crashed motorcycle riders. The second is a long-term naturalistic riding study, akin to the 100 car study conducted by Virginia Tech. Naturalistic studies enable investigations to study not only crash situations where things have gone irretrievably wrong, but situations in which the road-user was able to recover from potentially disastrous situations. This approach is in line with current research in human error, in which the recovery from human error and avoidance of negative outcomes is a strong focus of research"

    Given that government-funded or inititiated studies always find what the government wants them to find, I sense the looming presence of Big Brother yet again.
     
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  4. Thanks for the link Kishy.

    Seems to be telling me that rider inexperience, and THC and/or BAC are the primary factors.

    Excessive speed is merely travelling at above the speed limit. In a land of ever decreasing speed limits, that's getting easier and easier to do.

    To explain that another way. If there's a road where everyone naturally wants to travel at 110kph, and you then decrease the speed limit to 70kph, then if people continue to travel at 110kph, then ALL accidents suddenly become ones of "excessive speed", despite there being no difference other than a number on a sign. The Black Spur and the Great Ocean Road are primary examples of this.

    The report also seems to be incorrectly labelling high capacity bikes as a risk, but it does not seem to have taken into account the bike capacity distribution in the market-place. ie. 4x more >250cc bikes were in accidents, but are there 4x more >250cc bikes on the road, nor not?

    To me, the article set out to demonise speed, as was its stated objective, and along the way discovered that inexperience, drugs, and riding a bike that you're not licensed to ride (ie. inexperience again), are far more likely to get you into trouble than anything else.

    So, having identified inexperience as THE major factor in speed-related accidents, the report then goes on to suggest that more draconian speed enforcement is the answer. (It does correctly address the BAC/THC issues though).

    Typical MUARC output.
     
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  5. Couple of (hasty) interpretations:
    - it's more dangerous to exceed the limit in a low-speed zone than it is in a higher speed zone. Kind of intuitively obvious when you think about it.
    - experienced riders seem to get into as much or more strife at safe speeds as they do above them. (Doesn't mean that faster is safer, though - just that other factors are more prevalent).
    - inexperienced riders do get into more trouble when speeding.

    Have I missed the definition of excessive speed? In Victoria, most legal limits are far below what most people consider safe.
     
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  6. It was stated in the first few paragraphs. It's any speed above the posted speed limit.
     
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  7. Wow. That's just extraordinary. The very premise of this study is that the posted speed limits are correct. Furthermore the aim of the study is to determine the role that "speed" played in the accident.

    This is so unscientific it is ludicrous.

    Stivor
     
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  8. It is MUARC after all.

    We should have that inscribed on a trophy for them.

    "... and the This is so Unscientific it's Ludicrous award goes to.... MUARC!! For services rendered to the state government's rhetoric department."
     
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  9. At a quick speed read, I actually thought it was quite good by MUARC standards. I was particularly pleased to see, in the intro, an acknowledgement of what we all know, ie that it is not inherently unsafe to exceed the speed limit and, as a corollary, it is not necessarily safe to travel at the speed limit.

    What I would be concerned about are the potential for this to be used to push for two things. The first is Intelligent Speed Control, about which I'm not too worried as a bike specific measure although I see it as inevitable for all vehicles in the long term.

    The other, I think much more worrying, area was the emphasis placed on bike size as a risk factor. I think we will soon see a strong push for capacity or power limits.

    It's worth remembering that our Euro counterparts successfully fought off such a push a few years ago. I just wish I had as much confidence in our local motorcycle lobby organisations as I did in the European ones.
     
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  10. I think they are pointing out the tautological nature of the premise of the study. Excess speed is defined as any speed above the posted speed limit. Excess speed is determined to be a risk factor (though this is clearly stated as an a-priori assumption). But speed limits are set on the basis of safety and risk.

    There are also huge problems with running so many different post-hoc statistical analyses on the same dataset without correcting their error levels. It doesn't look as if they've done that, and yet they are happy to run multiple analyses on the same dataset and report on the statistical significance they find. (If you have a p of 0.05 and run 20 different analyses, one of them should throw up a significant result according to the law of averages.) Given that the entire dataset was only 200 data points, that is just asking for false significance. I'd like to see a power analysis done on the statistical analyses they carried out.

    Add to this the fact that inappropriate speed was 'confidently judged'. As one police officer put it to me when I was making a statement about a very bad car crash I'd witnessed, "If they crashed, then they were driving too fast for the conditions." There's that tautology rearing up again. Inappropriate speed is a speed which might contribute to a crash, and they are "confidently judging" whether inappropriate speed contributed to crashes.
     
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  11. No.

    To have made a subjective, case by case evaluation of whether the speed involved was excessive without having the resources to do so would have been unscientific. Defining excessive speed as anything above the speed limit is a 'limitation' of the scope of the study but it is perfectly valid.

    Every report or study has limitations, at least here they are clearly stated and are not likely to be incorrect (an assumption on my part). Would the study have more credibility or be open to the same criticism is they replaced "<edit> excessive speed" with "speed above the legal limit" in the report?

    As many members here have stated many times before, one person's safe speed is not safe for another person. I think the problem here is a definitional one. Excessive speed by most peoples standards is judged by skill, experience, road conditions/weather and road familiarity. For the purposes of this study these factors cannot be reliably identified by the authors.

    EDIT: Also, remember that that the study considers and reports on excessive speeds separately to inappropriate speed: "excessive (defined as travelling over the speed limit) and inappropriate (for the conditions) speed." and the two distinct tables.
     
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  12. If it is an muarc study then their recommendation would be for more speed cameras.
    They are on the nose as their "studies" are always on the premise they get more money for favourable outcomes for govco. ie speed cameras
    They have form and have lost massive cred for it.
     
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  13. Did I misread/misinterpret this?:

    Two potential study methodologies are recommended. The first is a case-control study of motorcycle crashes involving in-depth examination of the crash scene to estimate crash speed and interviews with the rider to reveal the circumstances surrounding the appropriateness of the speed at the time of the crash, to compare with a random sample of non-crashed motorcycle riders. The second is a long-term naturalistic riding study, akin to the 100 car study conducted by Virginia Tech. Naturalistic studies enable investigations to study not only crash situations where things have gone irretrievably wrong, but situations in which the road-user was able to recover from potentially disastrous situations. This approach is in line with current research in human error, in which the recovery from human error and avoidance of negative outcomes is a strong focus of research.


    I read that as saying that rather than saying "you were going too fast" that they might look at it more of the view of "you were going too fast for your ability" because the second part reads to me as looking at others who successfully get around there faster without crashing and look at the reasons behind that. Wasn't it also stated in the report that the measures employed on cars to reduce crashes aren't necessarily going to work for bikes? If my interpretation is correct, isn't this the direction that a lot of riders would rather see it go than make a blanket speed reduction?

    To me, that paragraph is possibly looking at opening the door for us to get more training earlier on (maybe subsidised) so that the crashes which don't involve crazy speeds but the ones in which someone could have recovered from their error but didn't are reduced or wiped out.

    Inexperience is the major factor that led me to write off my bike. I shouldn't have crashed where I did on the Black Spur for the speed I was doing (below the posted speed limit) but I did.

    Based on MUARC's crude correlations, I should come back to riding around my late 30s and all will be sweet :p.
     
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  14. The whole "excessive speed" and "too fast for the conditions" classifications are also heavily clouded by operator skill/experience.

    I've witnessed an unskilled rider feel like he's not going to be able to make a corner, freeze up, hit the brakes and leave the road. It's an all-too-common survival reaction that affects a great number of inexperienced riders, and to a lesser extent, even a fair number of long-term riders at one time or another.

    The point being that a rider who fails to negotiate a corner and then crashes and dies, may not necessarily have been travelling at an inappropriate speed for the road conditions, just at an inappropriate speed for their existing skill level.

    Since there's no way of knowing that for certain, we're left with a study that as zenali suggests, will simply lump all single vehicle accidents into the inappropriate or excessive speed categories.

    My concern is two-fold.

    First is that a speed-centric study that does not (or can not) take into account each individual operator skill allows for no room to determine whether or not better operator training may have made the difference. The fact that an inexperienced rider can crash on a corner at half the speed of an experienced rider who does not crash, would strongly indicate that operator skill, and not speed, is the issue. My concern is that more riders will die, because the conclusion of the study is for more speed enforcement, which will do nothing to save the rider who gets in over their head.

    My second concern is that myopic studies of this kind tend to gravitate towards an attitude of "lowest common denominator" speed limit postings. If some inexperienced noob crashes at 70kph in a 100kph zone, then it doesn't matter if 10,000 other experienced riders didn't crash at 100kph, the only conclusion you can arrive at with that data is that a 60kph speed limit will have saved the rider's life, and this will apply downwards pressure on posted speed limit to cater for the lower common denominator, and turn everyone else into "criminals". The Black Spur and Great Ocean Roads speed limit downgrades from 100kph to 80kph are very recent examples of this thinking in action.

    My problem is that such a study can never discover that better rider training may save more lives than speed enforcement.
     
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  15. Flux, I think you're spot on with what you wrote there. I did almost everything you wrote about an inexperienced rider coming unstuck when I crashed.

    Didn't the MUARC study recommend the two crash investigation methods to take into account what your concerns are? It looks like it to me and that would go a long way towards preventing the natural reaction to automatically impose a speed limit reduction.
     
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  16. Well, yes, they would. Do I think that they will ever be done? No. All some minister is going to see here is that "speeding is bad", and that "the existing speed limits are possibly too high", and see the potential for a greater revenue stream.

    Excuse me for being cynical, but the day those two study approaches are ever undertaken in Victoria with government funding, given that they're not likely to point towards more speed camera revenue being the answer, well I reckon that'll be the day that it starts snowing in Singapore.
     
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  17. Yes, I pretty much agreed with what you have said.

    But is this is a problem with the methodology of the report?

    Given that it was commissioned by a govt. agency to inform public policy it appears to have agreed with their view of the world.
     
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  18. Unfortunately, you're 99.999999999999999999999999999999999999999999999999999999% likely to be correct. More money/revenue is generally what they're about because that's the easiest option. We can only hope some common sense will prevail.
     
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  19. This obviously plays a huge role. But there are other things that won't necessarily show up in a study like this. There are skidmarks leading to the site of a fatal accident on a moderately tight bend. Given the time of day, road surface, etc., the police conclude that the rider must have been going too fast, slammed on the brakes, and lost control. What they don't see is the Subaru WRX that was coming around the corner from the other direction on the wrong side of the road, causing the rider to hit the anchors.

    Given the same set of accident scene evidence you can have multiple possible scenarios. If the rider was perfectly able to navigate the corner at that speed, but is run off the road by another vehicle, is it still "too fast for the conditions"?

    A multivariate analysis does not magically make a rigorous study.
     
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  20. Well, the introduction tells us about all the factors involved and how they may have very little to do with speed, and yet in the end we're still presented with a simple 3-category system of "Excessive Speed", "Inappropriate Speed", or "Unknown Speed".

    It looks to me like the researcher who wrote the report really wants to do a proper in-depth study, and heck, I reckon I would even trust them to do that, but ultimately their hands are tied within the mission statement of the study, which is to ram the square peg of the multi-facted reasons for why riders crash and die, into the round hole of it all being classified in terms of speed.

    I hope that makes it clearer. They went out of their way to explain that it's FAR more than simply about speed in the introduction, but in the end, the study is forced to categorise its findings according to emotively labelled speed boxes.

    The mission statement for this report reminds me of that classic saying: When the only thing you're using is a hammer, then everything starts to look like a nail.

    Exactly!
     
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