As some of you would know, mandatory hi viz for learner riders is coming. The "evidence" used to support hi viz is as follows: The role of conspicuity measures in improving detection of motorcyclists in traffic was examined by Wells et al (BMJ 2004; 32, who reported a 37% reduction in risk for riders who wore reflective or fluorescent clothing. http://www.bmj.com/content/bmj/328/7444/857.full.pdf In the recommendation arising from the Inquiry into Motorcycle Safety, the Victorian Parliamentary Road Safety Committee paid a good deal of attention to the work of De Craen et al (2011), published by SWOV. De Craen highlights that brightly colored high-visibility clothing is more effective in an urban environments which, in Victoria, is where 80 per cent of 2-vehicle novice rider crashes occur (Victoria Police crash data, 2009-2013). http://www.swov.nl/rapport/R-2011-25.pdf Research regarding the role of conspicuity can also be found in Motorcycle Conspicuity – What Factors Have the Greatest Impact? http://www.intrans.iastate.edu/rese...h-reports/motorcycle_conspicuity_ii_w_cvr.pdf. This study found a significant increase in detection distance of brightly cloroured riders in both rural and urban settings. This more recent work may not have been available to the Parliamentary Committee when it made its deliberations as the report was not published until June 2012. This thread is to explore the pros and cons of the notion of hi viz and the validity of the research. Interestingly both of the first two research papers make mentions of the possible confounds in their population sample which may render their conclusions moot. (Note, Vicroads doesn't mention this!) The first paper tries robustly to rationalise the confound away, but it's been roundly condemned by many since it's release. Perhaps we can explore what these confounds mean in the posts ahead. @smileedude and other research heads, I'm looking at you! It really is an important notion to understand and why statistical studies on this topic are generally flawed and why a proper randomised trial is the only way to answer whether hi viz has any genuine efficacy. The third research paper is a simulator study asking participants to press a button when they first noted a bike. Yes, conspicuous bikes were noted further away than non conspicuous bikes, but the interesting fact that appears to have gone unnoticed about this study is that when given the task of noting bikes, ALL bikes were noted, even the dark ones. To me it reinforces the well understood human condition of you see what you expect to see. Given that most drivers don't expect to see bikes, they DON'T even when in plain sight. This is a common experience amongst riders and why we advise each other to "ride around like we're invisible", because for a lot of the time, we are invisible through NO PHYSICAL APPEARANCE FAULT OF OUR OWN. Clearly Vicorads has made the leap that if a bike is seen then it will be safer. However, the simulator study doesn't say any such thing. The other thing is even if we are seen, other cognitive issues, the most predominant one known as "time to arrival illusion" (it's even mentioned on the TAC Spokes site), means that drivers often incorrectly assess the bike's speed and distance, so they drive out into our path assuming we are further away - this is the classic "SMIDSY" type incident often leading drivers to believe we were speeding. Hi Viz will not help this cognitive issue in any way. What will help address this cognitive issue is awareness and education. For example, when I see a bike in the distance (i.e. awareness, I'm expecting and looking for bikes), I don't judge it's distance by how far away it looks - I scan the road all the way up to the bike and get a much truer sense of how far away it is. This is NOT common practice, but it should be (ie education). I will say this though, despite the fears of thin edge of the wedge stuff, I don't believe this is a first step move towards mandating all riders in hi viz. I think the notion comes from a genuinely well meaning place to help give our most vulnerable road users, novice riders, every edge they can on the road. As we know, on 3AW recently, the announcer expressed the opinion of many, even if hi viz doesn't help, it can't hurt. This is a very hard notion to shift but it is not a good notion to base new regulation on. Ok, over to you guys. Discuss!!