The "green" color ("safety green") we are talking about almost appears to fluoresce in many situations. From my observations, it's generally more visible than other colors from longer distances in dim/low-light conditions ("fluourescent orange" might be second in visibility). I suspect that there are conditions where it isn't any more visible than other colors but very few cases where it is worse and many cases where it's better.
It's well-established that it's visible (there's no point in making that argument). The question here is whether it is the most visible (your example doesn't provide an answer to that).
There's a reason that yellow-green is deemed the most generally conspicuous.
A range of wavelengths of light stimulates each of these receptor types to varying degrees. Yellowish-green light, for example, stimulates both L and M cones equally strongly, but only stimulates S-cones weakly. Red light, on the other hand, stimulates L cones much more than M cones, and S cones hardly at all; blue-green light stimulates M cones more than L cones, and S cones a bit more strongly, and is also the peak stimulant for rod cells; and blue light stimulates S cones more strongly than red or green light, but L and M cones more weakly. The brain combines the information from each type of receptor to give rise to different perceptions of different wavelengths of light.
Surely the visibility of the colour of your clothing is dependent on the colour of the background that you are against, as viewed by the viewer (in this case, presumably, the driver of the car). If you are riding against a white building, bus or billboard then black might be the best colour to be seen in. The good thing about day-glow orange, green and yellow isn't that they are bright colours, it is that they are rare colours. If the city was painted bright orange and trees grew in bright yellow and green, the choice of these for cycling would not be so obvious.
Personally I don't pay any attention to what colour clothing I wear on a bike, but I always ensure that I wear something highly reflective for when everything else turns to black. This is when it matters.
Newspaper report on hi-viz and motorcyclists:
I have a couple of floresent lime green t-shirts that I picked for for helping sag club rides. I have had more than one cyclist comment that I was very noticeable while wearing them.
Personally, I've found that when riding with flashing lights, I consistently get more space from drivers than when I ride without, so I disagree with your conclusion that the more safety stuff you have, the more people put you in danger.
I've worked in an underground coal mine. It's completely black down there and there aren't any street lights. Everyone wears shirts with special 3-M reflective tape sewn into them. You can see a dude about a mile away just pointing a weak flashlight in that direction. I was ambivalent until I did a little test myself. It's quite remarkable. The only dilemma for me is that I commute with a backpack. I wish my backpack had the 3-M tape sewn on it.
Reflective Flap on Backpack by joshua_putnam, on Flickr
As others have noted, there are a few statistically valid studies showing a safety benefit from high-viz, and reflective only works if the person you want to see it has a light source. So neither one is a magic bullet, might as well use both, plus active lighting, and defensive lane positioning, and maintain situational awareness.
The risk of cycling is already quite low if you don't do any of those things; do all of them an it's really a very safe activity.
A helmet gives the appearance that your head is armored for a crash. (A false impression, of course; helmets aren't really designed for vehicle impact forces, they're marginal for simply falling off a bike. But, for purposes of risk compensation, it's the perceived risk that matters.)
A blinking light warns that you're vulnerable, but doesn't provide any appearance of protection from impact.
Thus, at least theoretically, a helmet could induce motorists to provide less clearance; a tail light that heightens the impression of vulnerability could induce them to provide more clearance.
Don't hold your breath waiting for rigorous studies of these questions.
Then there's my theory that motorists are willing to put someone at risk if it'd no risk to themselves. I studied this by standing on a busy road so I was obscuring the outer perts of a parked car from the oncoming motorists. As they get closer they perceive me as "easy prey" and inch themselves to a line where they will pass me and create fear. Just when they're near, I step back about a foot to expose the side of the parked car. Remarkable how many drivers get a fright and veer markedly further away from where I was standing. Not exactly the topic for a PhD but worrying!Quote:
The theory behind risk compensation would suggest that motorists are more willing to put you at risk if they perceive you to be better protected against risk.
I can offer no scientific analysis, but it does occur to me that more "non-natural" flashing warning lights flash for a reason, and since that has become customary in most traffic situation, people have been "programmed" to recognize the purpose of a flashing light. I have alway ridden since then with my taillght blinking and I am confident that it is a safer approach.
As for the florescent green vs bright yellow debate, again I would suggest that the florescent green used is a "non-natural" occurring color and it will stand out more than any other color commonly seen. I believe that this, and the fact that it was found to be more visible when seen through a smokey environment, is why many if not most, rescue/firetrucks used on airfields are painted this color.
Obviously the more seen you can be = the more safe. However, I disagree with some that say yellow is a good color, I think yellow can work against you at times, especially when riding right before the sun sets, the glare from the sun will make it even harder to see yellow. Just an opinion. I prefer bright orange myself.
I said it before in this thread and I'll say it again, no single color will be best in all circumstances. A color that stands out the best against the background and visual clutter is what will be most conspicuous. In a straightforward example, Fluo green is not as good against light colored spring foliage as is fluo orange, which is not as good as fluo green against bright fall foliage. Yellow may be good in many circumstances, but certainly not in all.
IMO, there is no rational argument against attempting to make yourself as conspicuous as reasonably possible. What's reasonable, of course will be a matter of opinion, risk tolerance, fashion adherence, etc...
When I see a rider in drab colors, many words come to mind, but bright isn't one of them.
isn't the floresent lime green color good because even color blind people can see it?
It doesn't make sense to expect that drivers are making the calculation that it's less risky to collide with helmeted cyclists.
An alternative hypothesis is that motorists expect that helmeted riders don't ride as erratically/weaving.
"Risk compensation" hypotheses appear to be just like the unsupported "just so" stories of evolutionary psycology.